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Nutrient Cycling in Agroecosystems

, Volume 111, Issue 2–3, pp 141–153 | Cite as

Corn yields with organic and inorganic amendments under changing climate

  • Ping Liu
  • Haijun Zhao
  • Yan Li
  • Zhaohui Liu
  • Xinhao Gao
  • Yingpeng Zhang
  • Ming Sun
  • Ziwen Zhong
  • Jiafa Luo
Original Article

Abstract

We evaluated the productivity and sustainability responses of corn (Zea mays L.) cultivated in brown soil (FAO: Haplic Luvisol) to long-term fertilization (1983–2011) and climate change in Shandong Province, eastern China. The experimental system comprised a crop rotation of winter wheat and summer corn, with a control (CK) and four fertilization treatments consisting of nitrogen (N), phosphorus (P), and potassium (K), and organic manure (M) in various combinations (N, NP, NPK, NPKM). The average corn grain yields in the four fertilization treatments were 1.3–2.3 times greater than that of the control (CK) (P < 0.001). The sustainable yield index (SYI) ranged from 0.5 to 0.8. The four treatments and CK were ranked, from highest SYI to lowest, as follows: NPKM > NPK > NP > CK > N. Corn grain yields in N, NP, and CK significantly increased over time (P < 0.05), but remained relatively high and stable over time in the NPK and NPKM treatments. Soil organic matter content increased over time, and was highest in the NPKM treatment. Soil pH did not change significantly over time (P > 0.05). Bivariate correlation analyses showed that the corn grain yields in CK and the four treatments were significantly positively correlated with mean temperature difference (max–min) during the growth season (P < 0.05). The correlation coefficients were higher for CK, N, and NP than for NPK and NPKM treatments. Corn productivity was more sensitive to climatic changes under long-term imbalanced nutrient application or no fertilizer application.

Keywords

Long-term fertilization Climatic factor Corn productivity Soil organic matter Sustainable yield index Haplic Luvisol 

Introduction

Yield is the most important outcome of crop production, and the sustainability of crop yield is an important part of agricultural sustainability (Chaudhury et al. 2005). Studying the impact of the long-term fertilization on crop yields can provide theoretical support for the sustainable development of agriculture. Many studies have focused on changes in crop productivity and sustainability under long-term fertilization (Ghosh et al. 2003; Turner and Asseng 2005; Cai and Qin 2006; Zhang et al. 2009; Huang et al. 2010). Several indicators have been proposed to measure the sustainability of different nutrient management systems, for example, the sustainable yield index (SYI), total factor productivity (TFP; the ratio of total output value to the total cost of all inputs), partial factor productivity (PFP; the ratio of output value to a specific input), and agronomic efficiency (AE) (Ghosh et al. 2003). Singh et al. (1990) proposed the SYI, for which high values and low standard deviations indicate sustainability of the system, and low values and larger standard deviations indicate unsustainable management practices. Many studies have found that SYI is an important indicator of system productivity (Ghosh et al. 2003; Manna et al. 2005; Li et al. 2010). The larger the SYI value, the better the sustainability of the system (Bhattacharyya et al. 2008).

The combination of organic manure and chemical fertilizers leads to better yield sustainability than chemical fertilizer alone (Majumder and Mandal 2007). That is, appropriate fertilization can improve the SYI value. Manna et al. (2005) examined the effects of fertilizer and manure application on yield trends and sustainability of crops cultivated in a continuous rotation system in sub-humid and semi-arid tropical areas of India. They observed that the SYI values were considerably lower in the control (0.01–0.16), N (0.01–0.33), and NP (0.21–0.49) treatments than in the NPK (0.27–0.61) and NPK + FYM (farmyard manure) (0.36–0.70) treatments. Li et al. (2010) analyzed the sustainability of maize, rice, and wheat yields at 20 long-term fertilization experimental sites in China under different fertilization systems and ecological conditions. They found that fertilization, especially the combined application of NPK and manure, promoted the sustainability of crop yields, with SYI values of 0.66, 0.58, and 0.57 for rice, wheat, and maize, respectively (compared with SYI values of 0.36–0.47 in the N and NK treatments). Different farming and crop rotation methods can also affect the SYI values of crops (Ghosh et al. 2003; Sharma et al. 2005; Manna et al. 2005). For example, Sharma et al. (2005) reported that the SYI values of the crops in a sorghum–castor rotation were higher with a conventional tillage approach than under a minimum tillage approach. To maintain crop yields and soil quality in Alfisols, primary tillage and the application of organic residues and N were needed. Significantly greater SYIs were recorded in rice–wheat–jute (0.14–0.70) followed by soybean–wheat (0.02–0.62) and sorghum–wheat (0.02–0.41) (Manna et al. 2005). The SYI was higher in a groundnut–groundnut rotation cropping system (0.673) than in a groundnut–mustard (0.376) rotation cropping system (Ghosh et al. 2003).

Under long-term fertilization, crop yield is the result of many factors such as crop variety, soil fertility, management measures, and climatic factors. Agro-ecosystems and food production are sensitive to climate change (Kerr 2007). Therefore, global climate change poses a huge risk to food security (Schmidhuber and Tubiello 2007). In recent decades, many studies have focused on the relationship between long-term climate change and crop yields (Tao et al. 2006; Lansigan et al. 2000). However, the effect of climate on crops can be influential at a regional scale. Jones and Thornton (2003) predicted that corn (Zea mays L.) yields might fall by 10% in parts of Africa and Latin America by the year 2055 as a result of temperature increases and rainfall differences becoming less conducive to maize production overall. Research on corn production in the U.S. corn belt under future climate conditions showed that the impact of climate change depended on the choice of model, and the simulated results of different models showed different degrees and even directions of the effects of different factors (Brown and Rosenreng 1999). Xiong et al. (2007) reported that future climate change conditions could increase corn production in rainfed areas of China, but decrease production in irrigated areas. Most previous studies have used field production data in one or more areas directly, and have ignored the yield differences resulting from environmental and site factors including soil type, soil fertility, tillage, and cultivation methods (Xiao et al. 2008; Christopher and Shawn 2008). Long-term fertilization experiments in a fixed plot or area can reduce or eliminate the effects of such environmental and site factors on production, because such factors are relatively constant among the different treatments (Wang et al. 2010). Thus, climatic factors that affect crop yield changes can be clearly analyzed.

Corn is an important staple crop for food, livestock feed, and biofuels on a global scale (Cassman et al. 2003; Landis et al. 2008; Edgerton 2009). In China, corn accounted for 30.3% of the total grain production in 2008 (Yin 2009). Long-term fertilization experiments have provided important information to guide agricultural development (Leigh and Johnston 1994), and are valuable for detecting trends in yields and soil nutrient status, and for evaluating system sustainability. Many long-term experiments have examined the effects of fertilization on crop yields and soil properties in various countries (Gami et al. 2001; Camara et al. 2003; Fan et al. 2005), including China. At present, there are approximately 70 ongoing long-term fertilization experiments underway in China, and these trials cover China’s major soil types and cropping systems (Xu et al. 2015). Brown soil (FAO: Haplic Luvisol) is one of the main soil types in China. It accounts for 29.2% of the cultivated land area in Shandong Province, which is in the middle east of China (Li et al. 2008). There are two long-term fertilization experiment sites with brown soil in China at present; one is in northeastern China and the other in Shandong. In this study, we conducted field monitoring and analyses of multi-year data, including weather data, in the long-term (1983–2011) fertilization experiment under a wheat–corn rotation cropping system in brown soil in Shandong Province. Our objectives were: (1) to determine the effects of long-term fertilization on corn productivity and sustainability; and (2) to investigate the mechanisms underlying trends in corn yields, soil quality, and climate changes. We hypothesized that corn productivity would increase with different long-term organic and inorganic amendments. Further, we hypothesized that climate change would lower the sustainability of corn yield, irrespective of fertilizer regimes. The results of this study would help to better understand how fertilizers influence crop growth and provide more references for crop production simulations and forecasts under the conditions of regional climate change.

Materials and methods

Site description

The long-term field experiment was initiated in 1982 under a wheat–corn rotation cropping system at the farm of the Institute of Agricultural Resources and Environment, Shandong Academy of Agricultural Sciences (N36°40′; E117°00′, 27.5 m above sea level), Shandong Province, China. This site has a semi-humid monsoon climate (Yang et al. 2007). The mean annual temperature and rainfall are 14.8 °C and 693.4 mm, respectively. The average temperatures in July and January are 27.4 and − 1.2 °C, respectively. Rainfall is concentrated in July and August. The soil type is brown soil with clay loam texture. Table 1 summarizes the characteristics of the soil at study site at the start of the experiment.
Table 1

Selected physicochemical characteristics of studied soil (0–0.20 m depth) at start of experiment

Soil type

Soil texture

pH (1:5, soil/H2O)

Organic matter (g kg−1)

Clay (g kg−1)

CEC (c mol kg−1)

Total N (mg kg−1)

Total P (mg kg−1)

Available N (mg kg−1)

Available P (mg kg−1)

Available K (mg kg−1)

Brown soil

Clay loam

7.2

6.83

268

14.2

83

124

17.54

5.40

116.40

Experimental design

The experiment had a randomized complete block design with three replicates. The fertilization treatments were applied to soils in cement pools separated by cement walls. Each cement pool was 1.0 m × 1.0 m × 0.8 m (depth) without a bottom. The cement walls were 0.20 m thick. Before the start of the experiment, soil in its original state was added to the pools. The experiment consisted of a control (CK, no fertilizer) and four treatments: (1) inorganic N fertilizer (N); (2) inorganic N and phosphorus (P) fertilizer (NP); (3) inorganic N, P, and potassium (K) fertilizer (NPK); and (4) inorganic NPK fertilizer combined with manure (M) (NPKM). The inorganic N, P, and K fertilizers were urea, calcium superphosphate, and potassium chloride, respectively. The application rates of the inorganic fertilizers were N 187.5 kg ha−1, P2O5 150 kg ha−1, and K2O 150 kg ha−1 for both the wheat and corn crops. Fresh horse manure was applied at a rate of 25 Mg ha−1 before sowing wheat in autumn every year. The composition of the horse manure was as follows: water content, 40%; organic matter content, 560 g kg−1; total N content, 16.8 g kg−1; total P content, 10.0 g kg−1; total K content, 6.0 g kg−1. The N, P and K fertilizers were applied as basal fertilizers and then the soil was ploughed immediately afterwards.

Corn was sown in early June and harvested in late September. The final planting density was 100,000 plants per hectare. Irrigation, herbicides, and pesticides were applied during the growth period as necessary. The corn cultivar was Yedan 4 before 2005, and Zhengdan 958 since 2006. Corn was not planted in 2001 because the soil pools were relocated that year due to urban expansion. First of all, soil pools were disconnected by an excavator. The surrounding soil was dug up to 1 m deep, and then a steel floor was inserted under each soil pool, and around the walls. The secured soil pool was then carefully transported to the new experimental site. Therefore, it was unlikely that the indices such as soil bulk density and organic matter content would change due to migration. All aboveground crop biomass was removed from the plot after harvesting corn, simulating the practice of local farmers to remove corn residues to use as fuel. Grain yields were determined by harvesting the whole area of each plot. The sustainability of corn grain yield was determined by the SYI (Singh et al. 1990), which was calculated from corn grain yield data over the year as follows:
$${\text{SYI}} = \left( {{\text{Y}} - {\acute{\text{o}}}_{{{\text{n}} - 1}} } \right)/{\text{Y}}_{\text{m}}$$
where Y is the mean yield over the year, ón−1 is the standard deviation (SD) and Ym is the maximum yield obtained under a set of management treatments.

Soil sampling and analysis

Soil samples were collected by the core method after harvesting the corn crop in September 1983, 1986, 1988, 1990, 1993, 1996, 1998, 2000, 2004, 2006, and 2011 (Huang et al. 2010). In each plot, three cores were taken to a depth of 0.20 m and were mixed as a composite sample. The fresh soil samples were air-dried and then passed through a 2-mm sieve before analysis. Soil organic matter (SOM), pH, available N (AN), available P (AP), and available K (AK) in soil samples were determined. The analytical methods were as follows: SOM (wet oxidation method, SOM (g kg−1) = soil organic carbon (g kg−1) × 1.724), pH (1:5, soil/H2O), AN (alkali solution diffusion method), AP (Olsen method), AK (1 mol L−1 ammonium acetate extraction, flame photometer method). All methods have been described in detail by Bao (2000).

Weather data

Multi-year (1983–2011) weather data at the study site were acquired from the China Meteorological Science Data Sharing Service Network built by the China Meteorological Administration (http://cdc.cma.gov.cn/home.do). Mean temperature (T), mean maximum temperature (Tmax), mean minimum temperature (Tmin), and temperature difference (ΔT, Tmax minus Tmin) during the corn growing season (June to September) were calculated from these data. T was the average of the daily mean temperature of the growing season. Tmax was the average of the daily maximum temperature of the growing season. Tmin was the average of the daily minimum temperature of the growing season.

Data analysis

Analysis of variance (ANOVA) was performed to determine the effects of long-term fertilization on corn yields and soil properties. Means were tested using the least significant difference (LSD) with a significance level of P < 0.05. Linear regression analyses were used to determine the trends in corn yield and growth season weather parameters over time. The relationship between corn yields under different fertilization treatments and soil properties, and climate parameters in different growing seasons were evaluated by bivariate correlation analyses. All statistical analyses were performed using SPSS 16.0.

Results

Corn yields and sustainability

Statistical analyses of the mean corn grain yields (1983–2011) showed that fertilization significantly affected grain yield (Table 2). The corn grain yields were significantly higher in all four fertilization treatments (N, NP, NPK, NPKM) than in the CK (P < 0.001) (Table 2). The average corn grain yields in the four fertilization treatments were 1.3–2.3 times than that of the control. The four treatments were ranked, from highest corn grain yield to lowest, as follows: NPKM > NPK > NP > N, and the differences among them were highly significant (P < 0.001). The coefficients of variation (CV) of corn yields over the 28 years ranged from 10 to 25% (Table 2). The fertilization treatments and control were ranked, from highest CV of corn yields to lowest, as follows: N > CK > NP > NPK > NPKM.
Table 2

Mean yields of corn cultivated in brown soil of eastern China under long-term fertilization treatments and control (1983–2011) (n = 28 years)

Treatments

Mean corn yield (Mg ha−1)

SE

SD

CV (%)

CK

3.55 e

0.127

0.671

18.89

N

4.54 d

0.213

1.127

24.80

NP

6.05 c

0.178

0.942

15.58

NPK

7.20 b

0.187

0.990

13.74

NPKM

8.23 a

0.164

0.894

10.87

SE standard error, SD standard deviation, CV coefficient of variation

Different lowercase letters within the same column indicate significant differences among treatments (P < 0.05)

Corn grain yields in the CK and the N and NP and treatments increased significantly over time (P < 0.05) (Fig. 1). Corn grain yields in the NPK and NPKM treatments remained relatively high and stable over the 28 years (Fig. 1). The SYI values for the fertilization treatments and control ranged from 0.5 to 0.8 (Fig. 2), and ranked, from highest SYI to lowest, as follows: NPKM > NPK > NP > CK > N. The differences in SYI among the fertilization treatments and control were highly significant (P < 0.01).
Fig. 1

Corn yields from 1983 to 2011 in different treatments (n = 28 years). * and **Significance at P < 0.05 and P < 0.01, respectively

Fig. 2

Sustainable yield index (SYI) of corn in different treatments from 1983 to 2011 (n = 28 years)

Long-term fertilization effects on soil properties

The SOM content increased over time in all treatments and the CK from 1983 to 2006 (Fig. 3). In general, the SOM content was highest in the NPKM treatment, where it was significantly higher than those in the other three treatments and the CK from 1986 to 2006 (P < 0.01). The SOM content did not differ significantly among N, NP, NPK, and CK (P > 0.05). Soil AN increased from 1983 to 1988 and then decreased slowly thereafter in CK and the four treatments (Fig. 3). The soil AN was higher in the NPKM treatment than in the other treatments and the CK in 1983, 1990, 1993, and 1996 (P < 0.01). Soil AP increased from 1983 to 1998 and then decreased in the NP, NPK and NPKM treatments, but remained at a low level and did not change over time in the CK and the N treatment (Fig. 3). Soil AK generally decreased over time, but showed the greatest variability in the NPKM treatment (Fig. 3). In general, soil AK content was significantly higher in the NPK and NPKM treatments than in the other two treatments and the CK from 1983 to 2006 (P < 0.05). Figure 4 shows the mean soil pH values in September 2006 and 2011. The initial soil pH was 7.2 in 1982, and it did not change significantly over time (P > 0.05).
Fig. 3

Properties of top soil (0–0.20 m) in different treatments from 1983 to 2006 (n = 10 years)

Fig. 4

pH of top soil (0–0.20 m) in different treatments in 1982, 2006, and 2011 (n = 3 years)

Trends in weather parameters

The average T, Tmax, and Tmin during the corn growing period decreased slightly during the 28 years, but the trends were not significant (P > 0.05) (Fig. 5). The mean temperature difference and rainfall during the corn growing period increased slightly, but the trends were not significant (P > 0.05; Figs. 5, 6).
Fig. 5

Temperature parameters during corn growing season (June–September) from 1983 to 2011 (n = 28 years)

Fig. 6

Rainfall during corn growing season (June–September) from 1983 to 2011 (n = 28 years)

Correlations between corn yields and soil properties/weather parameters

The bivariate correlation analyses showed that the correlation coefficients between SOM content and corn yields under the fertilization treatments and the CK ranged from 0.294 to 0.482, and the correlations were not significant (P > 0.05) (Table 3). The corn grain yields in the NPKM treatment were significantly (P = 0.024) negatively correlated with soil AN after corn harvest (Table 3). The corn grain yields for the four fertilization treatments and control were significantly (P < 0.05) positively correlated with mean ΔT during the growth season (Table 4). The correlation coefficients between corn yields and ΔT were higher in the CK and the N and NP treatments than in the NPK and NPKM treatments. The corn grain yield in the N treatment was significantly (P = 0.039) negatively correlated with mean Tmin during the growth season (Table 4).
Table 3

Bivariate correlation coefficients between corn yield and soil properties (n = 10 years)

Treatments

SOM

AN

AP

AK

CK

0.467

− 0.397

− 0.308

0.027

N

0.401

− 0.408

− 0.187

− 0.096

NP

0.418

− 0.306

− 0.045

0.103

NPK

0.482

− 0.077

0.002

0.052

NPKM

0.294

− 0.735*

− 0.502

− 0.352

SOM soil organic matter, AN available nitrogen, AP available phosphorous, AK available potassium

*Correlation coefficient significant at P < 0.05

Table 4

Bivariate correlation coefficients between corn yield and weather parameters from 1983 to 2011 (n = 28 years)

Treatments

T

Tmax

Tmin

ΔT

Rainfall

CK

− 0.177

0.081

− 0.333

0.485**

− 0.203

N

− 0.285

0.025

− 0.393*

0.481**

0.048

NP

− 0.172

0.085

− 0.269

0.418*

− 0.049

NPK

− 0.117

0.121

− 0.173

0.354*

− 0.032

NPKM

− 0.173

0.049

− 0.278

0.381*

− 0.161

T mean temperature, Tmax mean maximum temperature, Tmin mean minimum temperature, ΔT temperature difference (Tmax minus Tmin) during corn growing season from June to September

* and **Correlation coefficients significant at P < 0.05 and P < 0.01, respectively

Discussion

Effects of long-term fertilization on corn yields and yield sustainability

The results of this study showed that the application of inorganic fertilizers (N, NP, NPK) or inorganic fertilizers combined with organic manure (NPKM) significantly increased the production of corn cultivated in brown soil. The highest yield and production sustainability were in the NPKM treatment, consistent with the results of other studies. Manna et al. (2005) found that fertilizer treatments affected the SYI of crops and the highest production sustainability was in the NPK + FYM treatment, with the treatments ranked from highest SYI to lowest as follows: NPK + FYM > NPK > NP > N > CK. In contrast to the results of Manna et al. (2005), we found that the yield of corn was significantly higher in the N treatment than in the CK, but the CV and SD values were higher and so the SYI value was lower. Thus, the sustainability of corn yield was lower in the N treatment than in the CK. This may be related to the imbalanced nutrient supply resulting from application of only N fertilizer. The corn plants had insufficient nutrients for growth, and so their growth was more vulnerable to the effects of environmental factors, the yield was unstable, and the yield sustainability decreased. Li et al. (2009a) studied the sustainability of corn production under five different fertilization treatments at 22 long-term (10–28 years) fertilization sites in China, and they also found that long-term application of N fertilizer alone cannot increase corn yield or yield sustainability. They ranked the treatments, from highest mean corn yield to lowest, as follows: NPKM (6092 ± 564.4 kg ha−1, n = 15) ≈ NPK (5912 ± 639.2 kg ha−1, n = 17) > NP (4857 ± 449.3 kg ha−1, n = 20) > N (3876 ± 506.3 kg ha−1, n = 19) ≈ CK (3043 ± 406.1 kg ha−1, n = 22). When ranked based on their SYI values, the order of the treatments was as follows: NPKM (0.58 ± 0.032) ≈ NPK (0.57 ± 0.039) > NP (0.51 ± 0.040) > N (0.44 ± 0.046) ≈ CK (0.44 ± 0.043).

There are several explanations for the increase in corn production by long-term application of fertilizers and organic amendments (N, NP, NPK, or NPKM). First, a previous study at the same experimental site showed that after 10 years of continuous application of NPK fertilizers or NPKM, soil total organic P, inorganic P, and total K contents were higher than in the CK (Zhang et al. 2000). The total organic P content in the NPK and NPKM treatments were 0.9 times and 1.1 times than that of the control, respectively (total inorganic P content was 0.6 times and 0.8 times, higher, respectively). The total K content had only slightly increased, but the water-soluble K content was 2.7 times and 4.2 times higher in the NPK and NPKM treatments, respectively, than in the CK.

Secondly, SOM content of top soil had accumulated after 16 years of the N, NP, NPK, and NPKM treatments (Yu et al. 2002). The mean contents of humin-C and humic acids-C in the fertilization treatments were 93.7 and 74.9% higher, respectively, than those in the CK (Yu et al. 2002). In the NPKM treatment, the mean contents of humin-C and humic acids-C were 166.6 and 190.0% higher, respectively, than those in the control (Yu et al. 2002). Third, after 25 years of continuous N, NP, NPK treatments, the top soil porosity was higher and the bulk density was lower compared with those of the CK (Yang et al. 2007). The 25-year NPKM treatment resulted in further decreases in top soil bulk density and increases in soil porosity, thus improving the physical characteristics of the soil (Yang et al. 2007). Those results were obtained in previous studies at the same experimental site as that in our study.

In this study, we found that long-term fertilization with P and K increased the available P and K content in top soil, while the NPKM treatment significantly increased the organic matter content in top soil, compared with that in the CK (Fig. 3). Therefore, long-term N, NP, NPK, and NPKM treatments improved the physical characteristics of the top soil, including the organic matter and nutrient contents, thereby contributing to increase the yield of corn crops cultivated in brown soil.

Considering the input–output ratio, the economic benefits of the NPKM treatment and the NPK treatments are approximately equal. However, the NPKM treatment had greater effects to improve the SOM content and corn yield sustainability. Therefore, the balanced application of NPKM fertilizer is an important strategy for high and stable production of corn cultivated in brown soil, and represents the best fertilization method at present.

Growth season temperature difference affects corn production

The results of the correlation analysis showed that inter-annual variations in the yields of corn under long-term fertilization in brown soil were significantly correlated with the mean temperature difference during the corn growing season. The greater the temperature difference, the higher the corn yield. Most previous studies have focused on the relationship between corn yield and growth season temperature and/or precipitation, but few have focused on the relationship between corn yields and the growth season temperature difference. A previous long-term experiment on spring corn in China’s northeast rain-fed agricultural area showed that the corn yield was significantly negatively correlated with changes in the average Tmax during the growth season (Wang et al. 2010). A 1 °C increase in Tmax led to a 14% reduction in corn yield. However, the spring corn yield was not significantly correlated with the average Tmin or precipitation during the growing season. Lobell and Asner (2003) reported similar results for corn crops growing in the U.S. corn belt. Changes in the growth season temperature could explain about 25% of variations in corn yields, and climate warming reduced corn yields. A mean increase of 1 °C during the growing season was predicted to reduce corn yields by 17%. However, corn yield was significantly correlated with precipitation and with solar radiation. Statistical analyses have also shown that, on a global scale, an increase in growth season temperature is not conducive to corn production (Lobell and Field 2007).

The results of this study showed that an increase in the temperature difference during the growth season is conducive to an increase in corn production. This may because a greater temperature difference leads to accumulation of dry matter and the formation of crop yield. Two key processes in plant growth are photosynthesis and respiration, both of which are affected by temperature. Photosynthesis is mainly affected by high temperature during the day, and respiration by low temperature at night (Pan 2001). Therefore, as the temperature difference increases during the growth season, the accumulation of organic matter through photosynthesis will increase, thereby increasing corn yields. The higher correlation coefficients between corn yields and ΔT in the CK and N and NP treatments than in the NPK and NPKM treatments indicated that corn productivity was more sensitive to climatic changes when crops were cultivated with long-term imbalanced fertilization or no fertilizer.

Improvements in soil productivity by long-term fertilization

Long-term experiments have provided a wealth information on soil productivity under various fertilization practices. Many studies have shown that long-term application of chemical fertilizers without organic manure can decrease soil fertility. Such practices can lead to soil acidification and depletion of soil structure (Malhi et al. 2000; Graham et al. 2002; Malhi et al. 2003; Edmeades 2003). Instead, the balanced application of fertilizers helps to maintain soil productivity and can even slightly increase soil organic carbon content while increasing crop yields (Glendining et al. 1996; Kanchikerimath and Singh 2001; Shen et al. 2004; Manna et al. 2007). Manna et al. (2007) found that crop yields could be maintained in soybean–wheat rotation system after 30 years of continuous application of balanced fertilizers (NPK + lime or NPK + FYM), and that these fertilization practices positively affected soil C and N fractions and aggregate size distribution. Lithourgidis et al. (2006) studied the effect of continuous cropping on grain yields of wheat grown under the same conventional tillage practices for 25 years in four soils in northern Greece. In that study, N at 120 kg ha−1 and P2O5 at 60 kg ha−1 (applied as ammonium sulfo-phosphate) (20-10-0) were incorporated into the soil before disc harrowing each year. The results showed that despite the large variations in grain yields over time, there were no significant trends of yield decline in any of the four soils. In addition, there were no significant differences in soil pH values and organic matter content among treatments at the middle or the end of the experiment.

In this study, we found that corn cultivated with no fertilizer (CK) or with continuous fertilization (N, NP, NPK, or NPKM) did not show a decrease in grain yields over time. This result may be related to the soil type (brown soil) and/or the local climate characteristics. Long-term chemical fertilization did not result in acidification of brown soil. The studied brown soil has a clay loam texture, and it has a good water- and fertilizer-holding capacity. The study site is in northern China, where the accumulated temperature is lower, the daylight hours are longer, and the rainfall is lower than in southern China. Therefore, little N is lost by leaching, and crops are able to absorb N from the soil. The AN in topsoil were similar in the CK and all fertilization treatments after corn harvest (Fig. 3), indicating good use of the applied N by the corn plants. Li et al. (2009b) found that the corn, wheat, and rice yields in northern China were stable after about 20 years of NPK fertilization, while the crop yields at test sites in southern China showed a significant downward trend. They concluded that the hot and humid weather in southern China was not conducive to the preservation of nutrients, leading to relatively low soil nutrient contents. In addition, soil acidification was widespread among the sites in southern China, making it difficult to sustain high crop yields.

In this study, the aboveground biomass was removed, but the roots and stubble of the corn and wheat crops were left in the soil. Studies have shown that crop roots and stubble are important sources of SOM (Lithourgidis et al. 2006; Zhang et al. 2009). We found that the SOM content increased in all fertilization treatments and in the CK. An increase in SOM improves soil structure and provides certain nutrients such as N, P, K, and trace elements to subsequent crops (Cai and Qin 2006; Li et al. 2007). Ploughing of the roots and stubble of corn and wheat into soil was shown to decrease N leaching and increase soil N, leading to improvements in soil fertility (Meng et al. 2005). Meng et al. (2005) found that soil organic C and N contents were higher after long-term application of organic manure (wheat straw, oil cake, and cottonseed cake) than after long-term application of mineral fertilizers, indicating that crop straw could efficiently prevent N leaching and increase N content in the ploughed soil layer.

We suggest that the reason for the increased corn grain yield in the CK over time was related to N deposition as well as the increases in SOM content. Since the middle of the twentieth century, there has been a surge in the emission of active N compounds into the atmosphere, because of the production and use of chemical N fertilizers, the rapid development of animal husbandry, and other human activities. There has also been a rapid increase in atmospheric N deposition during this period (Galloway et al. 2014). The experimental site was located in Shandong Province, one of China’s most developed economic and agricultural regions. In 2010, the amount of N deposition in Shandong district was estimated at 30 kg ha−1 yr−1 (Zheng et al. 2014). Most N deposition including granular nitrate and ammonium salts occurs in the abundant rainfall months from June to September (Zheng et al. 2014), that is, the corn growing season. Therefore, although the CK plot was not fertilized, the addition of N to the soil via atmospheric N deposition might have contributed to the increase in corn yield over time.

Conclusions

Long-term fertilization (1983–2011) with balanced inorganic nutrients could significantly increase the production and sustainability of corn cultivated in brown soil in eastern China. The highest corn yield and sustainability was in the treatment combining NPK fertilizers and organic manure (NPKM); therefore, this fertilization method is recommended. The corn grain yields significantly increased over time in the CK and the N and NP treatments, and remained at relatively high and stable levels in the NPK and NPKM treatments. The characteristics of brown soil and the local climate, increased SOM content, and variations in mean temperature difference during corn growing season may have contributed to these yield increases/stable high yields. Corn productivity was more sensitive to changes in climatic factors under long-term cultivation with imbalanced nutrients or no fertilizer. Soil type, fertilization method, temperature differences during the growth season, and climate downscaling predictions should be considered in crop production simulations. Further research is still required to explore the mechanism of increased SOM and corn yields during long-term cultivation and fertilization in the studied brown soil.

Notes

Acknowledgements

This work was supported by National Key Research and Development Project (2017YFD0301002), the Special Fund for Agro-scientific Research in the Public Interest (201503112), the Natural Science Foundation of Shandong Province (ZR2016DB28), the Special Fund for Public Service Sector of National Environmental Protection Ministry (201203030), the Special Fund for “Oversea abroad Taishan Scholar” construction engineering of Jiafa Luo, and technological innovation project of Shandong Academy of Agricultural Sciences (CXGC2016B09).

References

  1. Bao SD (2000) Analysis of soil agrochemistry. China Agriculture Press, Beijing, pp 30–107 (in Chinese) Google Scholar
  2. Bhattacharyya R, Kundu S, Prakash V, Gupta HS (2008) Sustainability under combined application of mineral and organic fertilizers in a rainfed soybean–wheat system of the Indian Himalayas. Eur J Agron 28:33–46CrossRefGoogle Scholar
  3. Brown RA, Rosenreng NJ (1999) Climate change impacts on the potential productivity of corn and winter wheat in their primary United States growing regions. Clim Change 41:73–107CrossRefGoogle Scholar
  4. Cai ZC, Qin SW (2006) Dynamics of crop yields and soil organic carbon in a long-term fertilization experiment in the Huang-Huai-Hai plain of China. Geoderma 136:708–715CrossRefGoogle Scholar
  5. Camara KN, Payne WA, Rasmussen PE (2003) Long-term effects of tillage, nitrogen, rainfall and nitrogen levels on wheat yield. Agron J 95:823–835CrossRefGoogle Scholar
  6. Cassman KG, Dobermann A, Walters DT, Yang HS (2003) Meeting cereal demand while protecting natural resources and improving environmental quality. Annu Rev Environ Resour 28:315–358CrossRefGoogle Scholar
  7. Chaudhury J, Mandal UK, Sharma KL, Ghosha H, Mandalc B (2005) Assessing soil quality under long-term rice-based cropping system. Commun Soil Sci Plant 36:1141–1161CrossRefGoogle Scholar
  8. Christopher JK, Shawn PS (2008) Impacts of recent climate change on Wisconsin corn and soybean yield trends. Environ Res Lett 3:034003CrossRefGoogle Scholar
  9. Edgerton MD (2009) Increasing crop productivity to meet global needs for feed, food, and fuel. Plant Physiol 149:7–13CrossRefPubMedPubMedCentralGoogle Scholar
  10. Edmeades DC (2003) The long-term effects of manures and fertilizers on soil productivity and quality: a review. Nutr Cycl Agroecosyst 66:165–180CrossRefGoogle Scholar
  11. Fan TL, Stewart BA, Payne WA, Wang Y, Luo JJ, Gao YF (2005) Long-term fertilizer and water availability effects on cereal yield and soil inorganic properties in northwest China. Soil Sci Soc Am J 69:842–855CrossRefGoogle Scholar
  12. Galloway JN, Winiwarter W, Leip A, Leach AM, Bleeker A, Erisman JW (2014) Nitrogen footprints: past, present and future. Environ Res Lett 9:115003CrossRefGoogle Scholar
  13. Gami SK, Ladha JK, Pathak H, Shah MP, Pasuquin E, Pandey SP, Hobbs PR, Joshy D, Mishra R (2001) Long-term changes in yield and soil fertility in a twenty-year rice-wheat experiment in Nepal. Biol Fertil Soils 34:73–78CrossRefGoogle Scholar
  14. Ghosh PK, Dayal D, Mandal KG, Wanjari RH, Hati KM (2003) Optimization of fertilizer schedules in fallow and groundnut-based cropping systems and an assessment of system sustainability. Field Crop Res 80:83–98CrossRefGoogle Scholar
  15. Glendining MJ, Powlson DS, Poulton PR, Bradbury NJ, Palazzo D, Li X (1996) The effects of long-term applications of inorganic nitrogen fertilizer on soil nitrogen in the Broadbalk wheat experiment. J Agric Sci 127:347–363CrossRefGoogle Scholar
  16. Graham MH, Haynes RJ, Meyer JH (2002) Changes in soil chemistry and aggregate stability induced by fertilizer applications, burning and trash retention on a long-term sugarcane experiment in South Africa. Eur J Soil Sci 53:589–598CrossRefGoogle Scholar
  17. Huang S, Zhang WJ, Yu XC, Huang QR (2010) Effects of long-term fertilization on corn productivity and its sustainability in an Ultisol of southern China. Agric Ecosyst Environ 138:44–50CrossRefGoogle Scholar
  18. Jones PG, Thornton PK (2003) The potential impacts of climate change on maize production in Africa and Latin America in 2055. Glob Environ Change 13:51–59CrossRefGoogle Scholar
  19. Kanchikerimath M, Singh D (2001) Soil organic matter and biological properties after 26 years of maize–wheat–cowpea cropping as affected by manure and fertilization in a Cambisol in semiarid region of India. Agric Ecosyst Environ 86:155–162CrossRefGoogle Scholar
  20. Kerr RA (2007) Global warming is changing the world. Science 316:188–190CrossRefPubMedGoogle Scholar
  21. Landis DA, Gardiner MM, Van der Werf W, Swinton SM (2008) Increasing corn for biofuel production reduces biocontrol services in agricultural landscapes. Proc Natl Acad Sci 105:20552–20557CrossRefPubMedGoogle Scholar
  22. Lansigan FP, de los Santos WL, Coladilla JO (2000) Agronomic impacts of climate variability on rice production in the Philippines. Agric Ecosyst Environ 82:129–137CrossRefGoogle Scholar
  23. Leigh RA, Johnston AE (1994) Long-term experiments in agricultural and ecological sciences. In: Proceedings of a conference to celebrate the 150th anniversary of Rothamsted experimental station. Rothamsted Experimental Station, Harpenden, UKGoogle Scholar
  24. Li BY, Zhou DM, Cang L, Zhang HL, Fan XH, Qin SW (2007) Soil micronutrient availability to crops as affected by long-term inorganic and organic fertilizer applications. Soil Tillage Res 96:166–173CrossRefGoogle Scholar
  25. Li Y, Yu XW, Gao BM, Dong XX, Zhang YP (2008) Effect of long-term fertilization on potassium availability in three soil types and yield of wheat in Shandong Province. Chin J Eco Agric 16(3):583–586 (in Chinese) Google Scholar
  26. Li ZF, Xu MG, Zhang HM, Zhang WJ (2009a) Effects of different long-term fertilizations on sustainability of maize yield in China. J Maize Sci 17(6):82–87 (in Chinese) Google Scholar
  27. Li ZF, Xu MG, Zhang HM, Zhang WJ, Gao J (2009b) Grain yield trends of different food crops under long-term fertilization in China. Sci Agric Sin 42(7):2407–2414 (in Chinese) Google Scholar
  28. Li ZF, Xu MG, Zhang HM, Zhang SX, Zhang WJ (2010) Sustainability of crop yields in China under long-term fertilization and different ecological conditions. Chin J Appl Ecol 21(5):1264–1269 (in Chinese) Google Scholar
  29. Lithourgidis AS, Damalas CA, Gagianas AA (2006) Long-term yield patterns for continuous winter wheat cropping in northern Greece. Eur J Agron 25:208–214CrossRefGoogle Scholar
  30. Lobell DB, Asner GP (2003) Climate and management contributions to recent trends in U.S. agricultural yields. Science 299:1032CrossRefPubMedGoogle Scholar
  31. Lobell DB, Field CB (2007) Global scale climate-crop yield relationships and the impacts of recent warming. Environ Res Lett 2:014002CrossRefGoogle Scholar
  32. Majumder B, Mandal B (2007) Soil organic carbon pools and productivity relationships for a 34 year old rice–wheat–jute agroecosystem under different fertilizer treatments. Plant Soil 297:53–67CrossRefGoogle Scholar
  33. Malhi SS, Harapiak JT, Nyborg M, Gill KS (2000) Effects of long-term applications of various nitrogen sources on chemical soil properties and composition of bromegrass hay. J Plant Nutr 23:903–912CrossRefGoogle Scholar
  34. Malhi SS, Harapiak JT, Karamanos R, Gill KS, Flore N (2003) Distribution of acid extractable P and exchangeable K in a grassland soil as affected by long-term surface application of N, P and K fertilizers. Nutr Cycl Agroecosyst 67:265–272CrossRefGoogle Scholar
  35. Manna MC, Swarup A, Wanjari PH, Ravankar HN, Mishra B, Saha MN, Singh YV, Sahi DK, Sarap PA (2005) Long-term effect of fertilizer and manure application on soil organic carbon storage, soil quality and yield sustainability under sub-humid and semi-arid tropical India. Field Crop Res 93:264–280CrossRefGoogle Scholar
  36. Manna MC, Swarup A, Wanjari RH, Mishra B, Shahi DK (2007) Long-term fertilization, manure and liming effects on soil organic matter and crop yields. Soil Tillage Res 94:397–409CrossRefGoogle Scholar
  37. Meng L, Ding WX, Cai ZC (2005) Long-term application of organic manure and nitrogen fertilizer on N2O emissions, soil quality and crop production in a sandy loam soil. Soil Biol Biochem 37:2037–2045CrossRefGoogle Scholar
  38. Pan RC (2001) Plant physiology. High Education Press, Beijing, pp 55–121 (in Chinese) Google Scholar
  39. Schmidhuber J, Tubiello FN (2007) Global food security under climate change. PNAS 104:19703–19708CrossRefPubMedGoogle Scholar
  40. Sharma KL, Mandal UK, Srinivas K, Vittal KPR, Mandal B, Kusuma GJ, Ramesh V (2005) Long-term soil management effects on crop yields and soil quality in a dryland Alfisol. Soil Tillage Res 83:246–259CrossRefGoogle Scholar
  41. Shen J, Li R, Zhang F, Fan J, Tang C, Rengel Z (2004) Crop yields, soil fertility and phosphorus fractions in response to long-term fertilization under the rice monoculture system on a calcareous soil. Field Crop Res 86:225–238CrossRefGoogle Scholar
  42. Singh RP, Das SK, Rao UMB, Reddy MN (1990) Towards sustainable dryland agricultural practices. Bulletin, CRIDA, Hyderabad, pp 5–9Google Scholar
  43. Tao FL, Yokozawa M, Xu YL, Hayashi Y, Zhang Z (2006) Climate changes and trends in phenology and yields of field crops in China, 1981–2000. Agric For Meteorol 138:82–92CrossRefGoogle Scholar
  44. Turner NC, Asseng S (2005) Productivity, sustainability, and rainfall-use efficiency in Australian rainfed Mediterranean agricultural systems. Aust J Agric Res 56:1123–1136CrossRefGoogle Scholar
  45. Wang CC, Huang S, Deng AX, Chen CQ, Zhang WJ (2010) Correlations between climatic warming trends and corn yield changes in rain-fed farming areas of northeast China. J Maize Sci 18(6):64–68 (in Chinese) Google Scholar
  46. Xiao GJ, Zhang Q, Yao YB, Zhao H, Wang RY, Bai HZ, Zhang FJ (2008) Impact of recent climatic change on the yield of winter wheat at low and high altitudes in semi-arid northwestern China. Agric Ecosyst Environ 127:37–42CrossRefGoogle Scholar
  47. Xiong W, Matthews R, Holman I, Lin E, Xu Y (2007) Modelling China’s potential maize production at regional scale under climate change. Clim Change 85:433–451CrossRefGoogle Scholar
  48. Xu MG, Lou YL, Duan YH (2015) National long-term soil fertility experiment network in arable land of China. China Land Press, Beijing, pp 2–5 (in Chinese) Google Scholar
  49. Yang G, Zhang YP, Wei JL, Gao BM, Li Y, Dong XX (2007) Effects of long-term chemical fertilization on soil physical properties of three soils in Shandong Province. Chin Agric Sci Bull 23(12):244–250 (in Chinese) CrossRefGoogle Scholar
  50. Yin C (2009) Food security and global stability: global food crisis and food security in China. China Economic Publishing House, Beijing (in Chinese) Google Scholar
  51. Yu SF, Yang L, Zhang YL, Liu WY (2002) Influence of long-term fertilization on humus composition of soil. Chin J Soil Sci 33(3):165–167 (in Chinese) Google Scholar
  52. Zhang SM, Yu SF, Liu GD, Yan H (2000) Different fractions of phosphorous and potassium in soils as affected by successive fertilization. Plant Nutr Fertil Sci 6(4):375–382 (in Chinese) Google Scholar
  53. Zhang WJ, Xu MG, Wang BR, Wang XJ (2009) Soil organic carbon, total nitrogen and grain yields under long-term fertilizations in the upland red soil of southern China. Nutr Cycl Agroecosyst 84:59–69CrossRefGoogle Scholar
  54. Zheng DN, Wang XS, Xie SD, Duan L, Chen DS (2014) Simulation of atmospheric nitrogen deposition in China in 2010. China Environ Sci 34(5):1089–1097 (in Chinese) Google Scholar

Copyright information

© Springer Science+Business Media B.V., part of Springer Nature 2018

Authors and Affiliations

  • Ping Liu
    • 1
    • 2
  • Haijun Zhao
    • 3
  • Yan Li
    • 1
    • 2
  • Zhaohui Liu
    • 3
  • Xinhao Gao
    • 3
  • Yingpeng Zhang
    • 1
    • 2
  • Ming Sun
    • 1
    • 2
  • Ziwen Zhong
    • 1
    • 2
  • Jiafa Luo
    • 1
    • 4
  1. 1.Institute of Agricultural Resources and EnvironmentShandong Academy of Agricultural SciencesJinanChina
  2. 2.Key Laboratory of Agro-Environment in Huang-Huai-Hai-PlainMinistry of AgricultureJinanChina
  3. 3.Shandong Academy of Agricultural SciencesJinanChina
  4. 4.AgResearchRuakura Research CentreHamiltonNew Zealand

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