Yield Responses of Wheat to Crop Residue Returning in China: A Meta‐Analysis

Abstract

Crop residue returning (CRR) is known to improve the soil environment and thus increase crop production. However, the impacts of CRR on wheat (Triticum aestivum L.) yield have been contrary at times due to the differences in climatic conditions, soil traits, and management practices. These effects were evaluated using 351 paired observations published in 161 papers comprising studies conducted in 19 provinces (autonomous regions) of China. No publication bias or extreme values were found in the data, indicating that the analysis results are highly reliable. Compared with the practice of no crop residue returning (NCRR), the practice of CRR increased wheat yield significantly, on average by 8.29%, and proved more beneficial in Northwest China and in regions with average annual precipitation of 200 to 400 mm, average annual temperatures >11°C, sandy loam soil, and rotation with legumes (soybean [Glycine max (L.) Merr.]–wheat and pea [Pisum sativum L.]–wheat). The following aspects of CRR and crop management conferred greater benefits in yield: continuing the practice for 3 to 6 yr (compared with 1–2, 7–10, and ≥11 yr), using the residues at 3 to 6 t ha−1 (compared with <3, 6–9, and > 9 t ha−1), chopped straw (compared with intact straw), rainfed conditions (compared with irrigated conditions), and applying N at 200 to 300 kg ha−1 (compared with <100, 100–200, and >300 kg ha−1). The yield increase was significantly higher when the residues were returned in the form of mulch (12.56%) and for spring wheat (11.90%) than plowing them back into soil (4.53%) and for winter wheat (7.09%). The meta‐analysis thus confirms the benefits of CRR in higher wheat yields in China and also suggests that the benefits of CRR are site specific.

Effect of conservation tillage on yield of spring wheat (<i>Triticum aestivum</i> L.) and soil mineral nitrogen and carbon content

“…Residue incorporation, straw-return, and the reduction or even elimination of soil inversion are the most valuable approaches to the sustainability of agriculture. Straw has the potential to increase nutrient availability and facilitate the agronomic traits of crops (Han et al, 2020;Qi et al, 2019;Zhao et al, 2019). NT has different advantages including the improved physical properties of soil, reduced soil runoff, and increased crop production (Omara et al, 2019).…”

“…Both the application of residue incorporation into the soil and residue-return to the soil has led to positive effects on the level of soil nutrients, and this accordingly improves crop productivity (Han et al, 2020;Zhao et al, 2019). Residue incorporation into the soil indicates the restoration of losses of carbon to the environment of quantities up to 22 Tg C and straw-return restores carbon losses to amounts reaching 28 Tg C per year (Qi et al, 2019).…”

Maize yield and nitrogen-use characteristics were promoted as consistently improved soil fertility: 6-year straw incorporation in Northeast China

“…In order to stabilise high crop yield, Chinese farmers were used to applying large amounts of mineral nitrogen (N) fertiliser instead of organic fertiliser (such as crop straw), further lowering the soil quality and leading to environmental pollution due to the loss of excessive N (emitted to water or atmosphere). Making full use of harvested straw was believed to be the foundation for realising sustainable and environment-friendly agriculture in China (Liu et al 2014.Inputting the straw back to the field has been interestingly regarded as a promising field practice, as it can support higher crop productivity as a result of replenished soil fertility, bolstered soil physical properties and reduced crop water consumption (Qi et al 2019). Soil nutrient indices (especially soil microbial properties) are generally monitored to capture and compare the performances of field practices on soil quality, as they play vital roles during soil nutrient cycling.…”

“…Inputting the straw back to the field has been interestingly regarded as a promising field practice, as it can support higher crop productivity as a result of replenished soil fertility, bolstered soil physical properties and reduced crop water consumption (Qi et al 2019). Soil nutrient indices (especially soil microbial properties) are generally monitored to capture and compare the performances of field practices on soil quality, as they play vital roles during soil nutrient cycling.…”

Exploring optimal film mulching to enhance potato yield in China: A meta‐analysis

“…The continuous planting of the same, or closely related, crops for a long time has many negative effects, such as the abnormal accumulation or excessive consumption of soil nutrients, propagation of pathogenic microorganisms, continuous accumulation of allelochemicals, imbalances in the microbial population structure, and the frequent occurrence of pests and diseases (Qi et al., 2019; Yin et al., 2018). In contrast, crop rotations may utilize soil nutrients reasonably and maintain soil fertility by exploiting the differences in the requirements of different crops for soil ecological factors (Yang et al., 2014).…”