Replacing Synthetic Nitrogen Fertilizer with Different Types of Organic Materials Improves Grain Yield in China: A Meta-Analysis

Abstract

Synthetic nitrogen fertilizer substitution (NSS) with different types of organic material is a cleaner agricultural practice for reducing the application of synthetic N input in farmlands while also relieving the environmental issues caused by the discharge of organic wastes. However, the effects of the NSS practice on crop yields, being the primary objective of agricultural activity, is still uncertain in China. This study conducted a meta-analysis to assess the impacts of the NSS practices with different types of organic materials on crop yields. Results showed that the average crop yield was increased by 3.4%, with significant differences under NSS, thereby demonstrating that this practice contributed to improving crop yields, especially of rice and maize. According to published reports, the NSS practices involving chicken manure, pig manure, and crop straw increased crop yields by 4.79, 7.68, and 3.28%, respectively, with significant differences, thus demonstrating the superior effects needed for replacing synthetic N fertilizer. Moreover, substitution ratios (SR) between 0% and 60% could be suggested when using the NSS practice, with the high SR recommended when the original soil fertility was adequate for crops. Considering the long-term effects of applied organic materials, improving the grain yield with the NSS practice should be expected in the long-term. By effectively applying the NSS, this study attempted to scientifically decide on the type of organic materials and the appropriate SR based on the conditions of the soil and the crop. The results provide research information for the development of clean agricultural production and food security in China.

Responses of Soil Carbon Pools and Carbon Management Index to Nitrogen Substitution Treatments in a Sweet Maize Farmland in South China

“…This characteristic is beneficial to the nutrient supply and yield improvement of crops. Related studies have also shown the effect on production increase [39][40][41][42]. However, this study indicated that the contribution of organic materials to PC was small, although the total SOC s increased.…”

Effects of different tillage and fertilizer on soil quality under wheat‐maize rotation in the North China Plain

“…Furthermore, the enhancement of SQ through the application of both organic and inorganic fertilizers has been validated as a means to secure sustainable crop yields (Ren et al, 2022). Substituting synthetic nitrogen fertilization has exhibited a notable capacity to elevate crop yields by 3.28%–7.68%, further corroborating a significant positive correlation between the crop yields and SQ (Fan et al, 2021). Implementation of reduced tillage methodologies has demonstrated a propensity to ameliorate soil's physical attributes, fostering conducive conditions for root development and optimal water movement, particularly in dense clay soils (Saglam et al, 2015).…”

“…Furthermore, the enhancement of SQ through the application of both organic and inorganic fertilizers has been validated as a means to secure sustainable crop yields (Ren et al, 2022). Substituting synthetic nitrogen fertilization has exhibited a notable capacity to elevate crop yields by 3.28%-7.68%, further corroborating a significant positive correlation between the crop yields and SQ (Fan et al, 2021).…”

Recent trends in nitrogen cycle and eco-efficient nitrogen management strategies in aerobic rice system

“…Shifts in the concentration ratio of NH 4 + –N and NO 3 – –N content change the response of rice cultivars to soil available N, where cultivars with modified root features and highly responsive to soil N pools show increased N accumulation than the cultivars less responsive to soil N pools and with low NUE. Coupled organic and inorganic N fertilizer application can increase the rice grain yield but essentially requires the genotype selection process through integrated approaches of japonica and indica rice varieties ( Farooq et al, 2021 ) via integrative progressive crop management that can improve NUE and other crop features in physiological and agronomic perspectives ( Fan et al, 2021 ; Deng et al, 2022 ).…”