Monitoring wheat nitrogen requirement and top soil nitrate for nitrate residue controlling in drylands

doi:10.1016/j.jclepro.2019.118372

Journal of Cleaner Production

Volume 241, 20 December 2019, 118372

https://doi.org/10.1016/j.jclepro.2019.118372 Get rights and content

Highlights

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Plastic film mulch resulted in more nitrate residue in soil at wheat harvest.
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Nitrogen for 1000 kg grain formation was same for mulch and no mulch wheats.
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Nitrate in top soil can be used to predict that in deep soil on dryland.
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Deep soil nitrate residue can be controlled by monitoring topsoil and N requirement.

Abstract

Nitrogen (N) fertilizer application is an essential way to keep the high yielding crop production, but nitrate-N residue in agricultural soils has attracted wide attentions due to its various environmental effects. Understanding the yield formation and its relation to the N uptake and requirement are urgently needed to reduce the nitrate-N residue for plastic mulched wheat production in drylands. A three-year location-fixed field experiment with five N rates was carried out to test the grain yield formation and N use characteristics of wheat and soil nitrate-N response to no mulch (NM) and plastic film mulch (PM) cultivations. Obtained results showed that the PM promoted the wheat growth and had higher maximum grain yield and biomass at the similar N rate, compared to the NM. Although wheat took up much more N from the soils under the PM, its N requirement for 1000 kg grain formation (N_R) showed no significant difference from that of the NM, and for management of N fertilization, the same N_R can be used for both cultivations in dryland. Nitrate-N content in 0–20 cm top soil (S_NC) was found lower under NM than that under PM, but nitrate-N residue in 0–100 cm soil (S_NR) showed no significant difference between these two cultivations. The S_NR was significantly and linearly correlated with the S_NC under both cultivations, and thus the S_NC is able to be used to predict the S_NR. Therefore, the present work provides a feasible way or an idea to use the top soil nitrate content, wheat grain yield and its N requirement to optimize the N application rates and N fertilizer recommendation for wheat production and soil nitrate-N residue control in dryland.

Introduction

Rainfed agriculture covers about 80% of the cultivated land and produces 60% of the food for the world population (UNESCO, 2009). Wheat is one of the stable food crops and feeds about 30% of the world population (FAO, 2016), and about 75% of the wheat is produced from the dryland area (Li, 2004; Barakat et al., 2013; Khan et al., 2017). Due to the sparsely and unevenly distributed precipitation, wheat yield is usually low and fluctuant in drylands (Hemmat and Eskandari, 2004; Gao et al., 2009; Cazzato et al., 2013).

Plastic film mulch, as an efficient rainfall harvest technology (Yan and Dong, 2002), is widely applied worldwide for the purpose to increase crop yields (Ali et al., 2016). In Zaragoza of Spain, tomato yield was significantly increased by 171–379% in greenhouse covered with plastic film (Anzalone et al., 2017). Rainfed maize yield was 3805 kg ha⁻¹ under soil surface mulched with plastic film, which was 31% higher than that in no mulch plots in semi-arid region of northern Mexico (Fisher, 1995). In India, winter wheat grain yield was 3059–4233 kg ha⁻¹ and 12%–15% higher with plastic film mulch than that with no mulch (Chakraborty et al., 2010). In northwest China, plastic film mulch significantly increased the winter wheat grain yield by 1212 kg ha⁻¹ and 34% (Chen et al., 2015a). Significant increase in crop production was proved mainly from the increased water harvest from precipitation, decreased soil water loss by evaporation, improved soil water and temperature condition, microbial activity and soil nutrient supply capacity, and then the transpiration and yield formation (Wang et al., 2014; Mo et al., 2016).

Chemical fertilizers play a key role in crop production, and more than 55% of the crop yield increase is from the chemical fertilizer use in recent decades (Wang et al., 2015). In 2016, fertilizer nitrogen (N) use in agriculture was about 1.1 × 10⁸ t worldwide, which was 19.8% higher than that in 2006. In addition, agricultural N use of China reached 28% of the world total in 2016 (FAO, 2016). Overuse of nitrogen fertilizer widely exists in conventional and plastic film mulch crop production systems. In Italy, soil mineral N was observed to reach 223 kg N ha⁻¹ at sweet pepper harvest, when N input was 310 kg N ha⁻¹ (Tei et al., 1999). In the Loess Plateau of China, soil nitrate-N residues were increased from 38 to 387 kg N ha⁻¹ in a winter wheat field at harvest, when the N input was increased from 0 to 320 kg N ha⁻¹ (Dai et al., 2016). In Virginia of USA, soil NO₃–N was 23.5 mg kg⁻¹ in top 15 cm soil of tomato field in plastic film mulched greenhouse, which was 236% higher than that with no plastic mulch (Schonbeck and Evanylo, 1998). Similar results were reported in a lettuce field at Hohenheim of Germany (Matitschka and Ernst, 1995). In Shaanxi province of China, in a winter oilseed rape field with plastic film mulched soil surface, nitrate-N was 24.0 mg kg⁻¹ in 0–30 cm soil at harvest, which was 18% higher than that with no mulch (Gu et al., 2018). Also, a meta-analysis showed that plastic film mulch increased soil nitrate-N residual in 0–20 cm soil layer at crop harvest in Northwestern China (Ma et al., 2018). Problems caused by N fertilizer overuse have attracted more and more attentions, and it is of vital significance to optimize and reduce the N fertilizer input for the sustainable crop production and environmental development.

In our previous study, a N fertilizer recommendation method (N_FR) (Fig. 1) was established for dryland winter wheat based on soil nitrate N test and N requirement (N_R) for the target grain yield, with the purpose to optimize the N application rate, reduce the nitrate residue in soil, and sustain and increase the crop yield under conventional cultivation (Huang et al., 2017). By this method, soil nitrate-N residues in 0–100 cm soil (S_NR) need to be determined at wheat harvest by taking soil samples from 0 to 100 cm soil. Obviously, this is difficult and impractical for farmers and agricultural service agents. If the nitrate-N in top 20 cm soil (S_NC) could be used to predict the S_NR, the method would be made more easily to use. Loess Plateau is a typical dryland in the world and the main dryland wheat production area in China, where 44% of the agricultural land was occupied by wheat and plastic film mulch is widely used (Gao et al., 2009). However, research about the N_R for the plastic film mulch wheat is still lacking. Therefore, a three-year field experiment was conducted at five N application rates with plastic mulched soil surface and no mulch in the Loess Plateau, for the purpose to 1) understand the winter wheat yield and N requirement difference under plastic film mulch and no mulch conditions; 2) identify the relationship of nitrate-N content in top 20 cm soil (S_NC) to nitrate-N residues in 0–100 cm soil (S_NR); 3) explore the possibility to modify the N_FR method by replacing nitrate N test in 0–100 cm soil (S_NR) with that in only 0–20 cm soil (S_NC) (Fig. 1).

Section snippets

Experimental site

Field experiment was conducted from 2014 to 2017 in Yongshou (34º43′ N, 108º10′ E), Shaanxi of China, a typical dryland area in the Loess Plateau with a temperate continental monsoon climate, annual temperature of 11.3 °C, annual precipitation of 570 mm, and annual potential evaporation of 1300 mm. Approximately 60% of the precipitation occurs during the summer fallow season (from July to September). Precipitation during the experimental years is shown in Fig. S1. Winter wheat is the main food

Wheat grain yield and biomass

Wheat grain yield and biomass all varied with the N fertilizer application rates in a linear-cross way (Fig. 2a and b). Regression analysis showed that the maximum grain yield was 4967 kg ha⁻¹ at the N application rate of 69 kg N ha⁻¹ for the NM, and it was 5311 kg ha⁻¹ at 60 kg N ha⁻¹ for the PM. Similarly, the maximum biomass was 11339 and 12338 kg ha⁻¹, respectively at 63 and 60 kg N ha⁻¹ for NM and PM (Fig. 2c and d). These results indicated that the PM produced a higher grain yield and

Differences of grain yield and aboveground biomass

Similarly as the previous studies in dryland (Chen et al., 2015b; He et al., 2016; Luo et al., 2018), plastic film mulch indeed increased the wheat grain yield (Fig. 2). Apart from the increased spike number observed in the present study due to the enhanced tillering (Zhou et al., 2009), more water harvested from limited precipitation (Chakraborty et al., 2008) and improved soil hydrothermal conditions especially in earlier growing stage of wheat were usually reported to be the main reasons for

Conclusion

Obtained results showed that the PM promoted the wheat growth and had higher maximum grain yield and biomass at the similar N rates, compared to the NM. Although the wheat took up much more N from soil under PM, its N requirement (N_R) showed no significant difference from that of NM, and the same N_R can be used for both cultivations in dryland. Nitrate-N content in 0–20 cm top soil was lower under NM than that under PM, but nitrate-N residue in 0–100 cm soil showed no significant difference

Acknowledgements

This research was supported by the National Key Research and Development Program of China, China (2018YFD0200401); China Agricultural Research System, China (CARS-3); Chinese National Science and Technology Support Program, China (2015BAD23B04); and Chinese Special Fund for Agro-scientific Research in the Public Interest, China (201503124).

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Citation Excerpt :
Nitrogen (N), when applied at an optimal rate, is fundamental to improving plant growth, physiology, and productivity (Ma et al., 2022; Momesso et al., 2022). However, excessive usage harms the environment due to leaching losses, denitrification, and ammonia (NH3) volatilization (Huang et al., 2017a; Zhang et al., 2019). High levels of residual NO3−-N in the soil can increase nitrate concentration in groundwater and contribute to soil nutrient imbalances which, in turn, threaten sustainable crop production (Haider et al., 2017).
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