Analysis of the Available Straw Nutrient Resources and Substitution of Chemical Fertilizers with Straw Returned Directly to the Field in China

Abstract

Returning straw to the field is the most significant straw utilization technique for China’s green development. It can provide nutrients for crop growth and improve soil organic matter content. However, there are no standard parameters for measuring the nutrient content of straw directly returned to the field. In addition, the nutrient content of straw in the field is disregarded and the least researched. Therefore, to address these issues, the current research examines the main nutrient composition of straw returned directly to fields and the potential substitution of straw for chemical fertilizers. This study used the latest data on the crop straw-to-grain ratio and straw’s direct return to the field from the Database of Agricultural Crops Straws Resources in China (DACSRC) as the basis for a detailed estimation of the amount of crop straw nutrient resources and straw’s direct return to the field. The straw nutrient resources were measured based on straw yield and the nitrogen (N), phosphorous (P2O5), and potassium (K2O) contents. The results reveal that the maximum amount of straw returned directly to the fields in China was 517 teragram (Tg), while 128 Tg (25%) of the total was not collected but left on the field. The North China region had an enormous amount of direct straw return at 176 Tg (34%), while South China had the least amount at 26 Tg (5%). The amounts of seasonally available N, P2O5, and K2O from straw directly returned to fields are 2 Tg, 1 Tg, and 7 Tg, respectively. In addition, the amount of available straw nutrient resources returned to the field per hectare (ha) was 78 kg. The quantity of straw-originating seasonally available nutrients corresponds to 23% of the chemical fertilizers applied, which can substitute 10% N, 9% P2O5, and 58% K2O. The study provides critical insights on effective ways to improve straw fertilization through an increased rate of straw returned directly to fields and releasing seasonal nutrients.

Straw return-enhanced soil carbon and nitrogen fractions and nitrogen use efficiency in a maize–rice rotation system

“…Previous reports have shown that straw return improved the soil N content and N uptake and reduces the soil N leaching (Huang et al, 2021). Besides, the decomposition of straw released C, N, P, and K into the soil, improving the soil nutrient status (Tables 2, S5, S6), which is in line with the report by Cui et al (2020a) and Shao et al (2023). According to the SEM analysis (Fig.…”

“…Possible reasons for this are that the positive impact of straw return on yield can be influenced by environmental conditions and management practices, which are closely related to the straw decomposition status. One of the major reasons for improvement in crop yield under straw return is the promotion of nutrient availability in the soil during straw degradation (Turmel et al, 2015;Shao et al, 2023). Our study observed a significant increase in soil Nmin, available P, and exchangeable K under straw return treatment (Table 2), which proved that the basic productivity of soil was enhanced after a 3-year straw return.…”

“…Studies have shown that the return of crop straw to the field is an effective and economically sound management practice to address cropland productivity degradation under the practices of intensified conventional tillage and high nitrogen input for food production (Xia et al, 2018;Huang et al, 2019). Straw return can increase crop yield by supplying mineral elements, improving soil physicochemical properties, and regulating soil microbial activity (Turmel et al, 2015;Cui et al, 2022a;Shao et al, 2023). However, these effects vary depending on conditions like straw quality, soil properties, climate conditions, straw returning method, and cropping types (Tian et al, 2019;.…”

Reduced Tillage, Application of Straw and Effective Microorganisms as Factors of Sustainable Agrotechnology in Winter Wheat Monoculture

“…The straw mulch leads to an improvement in soil chemical properties through increasing the concentration of available forms of macronutrients (N, P, K) and organic carbon in the top layers of soil [29][30][31]. According to Shao et al [32], nutrients from straw mineralization may be an effective source of nitrogen, phosphorus and potassium, replacing 10% N, 9% P 2 O 5 and 58% K 2 O from fertilizer application.…”

“…The negative aspects of mulching the soil with straw include the possibility to increase pests and diseases infestation in main crops [25,33,34]. Shao et al [32] stated that incorrect direct straw-returning practices may have negative effects for crop health and the number of pests and may also reduce the crop germination rate. However, the results of research on this issue are not clear.…”