Crop yield and soil organic matter after long-term straw return to soil in China

Abstract

Straw has been commonly incorporated to maintain soil fertility and crop productivity in China, but effects of long-term straw incorporation on crop yield, soil organic carbon (SOC) and total nitrogen (TN) have not been thoroughly evaluated. Thus, this study analyzed data collected in long-term ([10-year) trials across the major agricultural zones of China. Across the trials, relative to straw removal, straw return significantly increased crop yield, SOC and TN (by 7.0, 10.1 and 11.0 %, respectively). In some trials with winter wheat in northern China, straw return reduced yield by 0.6-7.1 %. The effects of straw return on SOC and TN were not significantly affected by experimental duration, land use type and cropping system, but positively and linearly related to the inputs of straw-C and -N, respectively. Interestingly, SOC and TN responses to straw return were decoupled in upland and upland-paddy soils in China, but not in paddy soils. Mean values of straw-C sequestration efficiency (7.7, 10.3 and 9.4 %, under corn, wheat and rice, respectively) indicate that 100 % straw return could increase SOC by 281.7 Tg C in 18 years (the mean experimental period of the considered studies) in China. Our analyses demonstrate that straw return is an effective practice for sustaining crop productivity and soil fertility in large parts of China, but sitespecific factors should be considered.

Straw incorporation increases crop yield and soil organic carbon sequestration but varies under different natural conditions and farming practices in China: a system analysis

“…This yield increase is similar in magnitude to a recent global analysis (12%; Liu et al 2014), but larger 20 than previous meta-analyses of published data from China (up to 9% increase;Zhao et al, 2015;Wang et al, 2015;Huang et al, 2013;Xu et al, 2017) and those of the EU (6% increase; Lehtinen et al, 2014).…”

“…3d); or more limited geographical spread, e.g. only NC was considered in (Xu et 25 al., 2017) and only three sites from NEC were included in the analysis by Wang et al (2015) and Huang et al (2013). According to the current cereal production level in China (616 million Mg; NBSC, 2016), this straw-induced yield increment (13.4%) results of additional 82.6 million Mg of agricultural products.…”

“…Integration of the results of studies covering different regions and under varied farming practices also assist an effective examination of the underlying mechanism of straw incorporation on SOC, (e.g. SOC conversion efficiency; Kong et al, 2005;Wang et al, 2015) and crop yield. This novel information could provide the scientific basic support for the development of sound 35 policy for straw management at regional and governmental levels (Ministry of Agriculture−PRC, 2013.…”

“…Wang et al (2015) reported that the estimated annual straw N input rate (39.6 kg N ha suggested that crop residue recycling determines the soil K balance and thus affects crop production substantially. Our analysis did observe a strong indication that maize yields benefited more (20.8%) from straw incorporation than those of wheat (8.7%) (Fig.…”

Response of Rice and Maize Yield to Inherent Soil Productivity of Paddies and Fertilization in Chongqing China

“…The difference of basic soil productivity was mainly due to the increase of organic matter content in soil [10]. In the past 20 years, the improvement of organic matter in cultivated land was mainly attributed to straw returning to field, the popularization and application of organic fertilizer, the application of synthetic fertilizers, and measures of no-tillage and minimum tillage [21], and long term returning straw to field could improve the content of organic matter and total nitrogen more than 10% [22].…”