Effects of Nitrogen Supply on Dry Matter Accumulation, Water-Nitrogen Use Efficiency and Grain Yield of Soybean (Glycine max L.) under Different Mulching Methods

Abstract

In dryland agriculture, mulching methods and nitrogen application have been extensively adopted to improve water and nitrogen use efficiency and increase crop yield. However, there has been a scarcity of research on the combined effects of mulching types and nitrogen application on the growth and yield of soybean (Glycine max L.). In the present study, four nitrogen levels (N0: 0 kg N ha−1, N1: 60 kg N ha−1, N2: 120 kg N ha−1, N3: 180 kg N ha−1) and four mulching methods (NM: no mulching, SM: straw mulching, FM: film mulching, SFM: straw and film mulching) were set so as to evaluate the effects of mulching methods and nitrogen application on dry matter accumulation, grain yield, water-nitrogen use efficiency, and economic benefits of soybean in Northwest China from 2021 to 2022. The results show that the dry matter accumulation, yield formation, water and nitrogen use efficiency, and economic benefits of soybean were improved under different mulching methods (SM, FM, and SFM) and nitrogen applications (N1-N3), and that the effect is the best when the nitrogen application rate is N2 and the mulching method is FM. As such, a conclusion could be drawn that suitable nitrogen application (120 kg ha−1) combined with film mulching was beneficial for the utilization of rainwater resources and soybean production in the dryland of Northwest China.

Research on potato (Solanum tuberosum L.) nitrogen nutrition diagnosis based on hyperspectral data

“…(2022) and X. Wang et al. (2023). The NNI (Lemaire et al., 2008) was determined using the equations as follows: $$$$\begin{equation}{\mathrm{NNI}} = {\mathrm{N}}/{{\mathrm{N}}_{\mathrm{c}}}\end{equation}$$$$ $$$$\begin{equation}{{\mathrm{N}}_{\mathrm{c}}} = {\mathrm{4}}{\mathrm{.57}}\,{\mathrm{D}}{{\mathrm{M}}^{ - 0.41}}\end{equation}$$$$…”

“…where y is the plot yield, kg and Y is the yield per hectare, kg ha −1 . The NUE was calculated with the equation as follows: $$$$\begin{equation}{\rm{N}}\;{\rm{utilization}}\;{\rm{efficiency\left( {NUE,\,kg\,k{g^{ - 1}}} \right)}} = \frac{Y}{{{N_{{\mathrm{uptake}}}}}}\end{equation}$$$$where $${Y_N}$$ is the Y with nitrogen applied (kg ha −1 ) and $${N_{{\mathrm{uptake}}}}$$ is the total nitrogen uptake (kg ha −1 ) (X. Wang et al., 2023).…”

“…For the chemical analysis methods, the readers can refer to S. H. Zhang et al (2022) and X. Wang et al (2023).…”

“…Guo et al (2022) and X. Wang et al (2023). The NNI (Lemaire et al, 2008) was determined using the equations as follows:…”

“…where 𝑌 𝑁 is the Y with nitrogen applied (kg ha −1 ) and 𝑁 uptake is the total nitrogen uptake (kg ha −1 ) (X. Wang et al, 2023).…”