Optimal Fertilizer Application Reduced Nitrogen Leaching and Maintained High Yield in Wheat-Maize Cropping System in North China

Abstract

Agricultural nitrogen (N) non-point source pollution in the North China Plain is a major factor that affects water quality and human health. The characteristics of N leaching under different N application conditions should be further quantified accurately in winter wheat (Triticum aestivum L.) and summer maize (Zea mays L.) rotation farmland in North China, and a basis for reducing the risk and evaluation of N leaching in this area. A three-year field experiment was conducted using an in situ leakage pond method at a typical farmland in Henan in 2017–2020. Crop yield, soil nitrate N residues, and N utilization were also studied during the study period. Five N fertilizer rates were established with 0 (CK), 285 (LN), 465 (MN), 510 (MNO), and 645 (HN) kg N ha−1 for one rotation cycle. MNO was applied with chemical and organic fertilizers. The concentration of nitrate N in the soil leaching solution of CK, LN, MN, MNO, and HN was 0.81-, 1.49-, 3.65-, 5.55-, and 7.57-fold that of the World Health Organization’s standard for underground drinking water. The exponential relationship between the N application rate and leaching was obtained when the annual N input exceeded 300 kg ha−1, and the N leaching rate increased greatly. The leaching rate of nitrate N in the total N was 50.6–82.4% under different treatments of N application. The combination of chemical and organic fertilizers treatment (MNO) reduced the amount of N that was leached in dry years. The nitrate leaching amount of summer maize accounts for 83.0%, 49.4%, and 72.0% of the total nitrate leaching amount of the whole rotation cycles in 2017–2020. LN and MN were recommended as the optimized N application here (285–465 kg N ha−1) with the two-season rotation grain yield of 17.2 ton ha−1 (16.5–17.9 ton ha−1) and nitrate N leaching of 21.6 kg ha−1 (12.6–30.5 kg ha−1).

Growth and yield of maize in response to reduced fertilizer application and its impacts on population dynamics and community biodiversity of insects and soil microbes

“…JA, SA, and JA-ILE belong to plant hormones that play a critical role in defense signal transduction (Eitle et al, 2019). Adverse conditions can significantly affect the production of these substances, which then play their anti-stress roles, such as pest and disease resistance (Schmelz et al, 2003;Couture et al, 2010;Batool et al, 2022).…”

“…Rigorous pot experiments have proved that reduced fertilizer application can increase the content of crop JA and other resistant substances (Song et al, 2020), but we did not find significant changes in the field experiments. We speculated that, this was because the crops in the North China Plain were cropped two times a year, the wheat straw was pulverized and returned to the field, and the wheat fertilizer residue and straw still provide N, P, K, and others, and studies supported this speculation which makes the impact of fertilizer reduction on corn even lower (Liu et al, 2016;Luo et al, 2022;Pu et al, 2022).…”

Assessing the Effect of Intensive Agriculture and Sandy Soil Properties on Groundwater Contamination by Nitrate and Potential Improvement Using Olive Pomace Biomass Slag (OPBS)

“…The surplus of nitrate exceeds the plants' demand and soil denitrification capacity [11] and leaches out of the root zone as one of the most common forms of groundwater contamination [12,13]. The leaching of nitrate from the soil is a major problem threatening surface and groundwater quality and therefore human health [14,15]. The nitrate form (NO 3 − ) of nitrogen is highly soluble, easily mobile within the soil, and poorly adsorbed by the soil particles.…”