No-tillage with total green manure mulching increases maize yield

Wheat–maize rotation is a widely used planting pattern in oasis-irrigated areas in Northwest China.  Although this planting pattern can somewhat break the barrier of continuous cropping, it also comes with limitations, such as large evaporation and prominent soil degradation during the fallow period,  restricting crop yield. 

Planting green manure after wheat and returning it to the field can effectively improve soil physicochemical properties, regulate photosynthetic characteristics of subsequent crops, and promote crop yield. However, the photosynthetic physiological mechanism of crop yield improvement under different green manure return methods remains unclear.

To that end, a team of researchers from China conducted a three-year field experiment at a research station in the Shiyang River Basin (Gansu, China). They explored the relationships among soil moisture and temperature environment, maize root structure, photosynthetic characteristics, fluorescence characteristics and yield under different green manure return methods.

“We evaluated five treatments in this study: (i) conventional tillage without green manure (CT), (ii) no-tillage with total green manure mulching (NTG), (iii) no-tillage with removal of aboveground green manure (NT), (iv) tillage with total green manure incorporation (TG), and (v) tillage with only root incorporation (T).” shares corresponding author Aizhong Yu, a professor at Gansu Agricultural University.

Their results, reported in the Journal of Integrative Agriculture, showed that the NTG and TG significantly increased soil water content in 0–110 cm soil layer, soil temperature of maize seedlings (V3) to jointing stage (V6), canopy cover, leaf stay-greenness, root length, net photosynthetic rate (P_n), transpiration rate (T_r), actual photochemical efficiency of PSII (ΦPSII), maize biomass, and grain yield compared with CT.

Notably, green manure return to the field could improve root structure and canopy coverage of maize mainly by improving soil water content. “The optimization of maize root structure and canopy coverage increased the maize chlorophyll content (SPAD) value and promoted P_n. The increase in P_n in turn inhibits the increase in NPQ, thus promoting the activation of ΦPSII. Ultimately, the increase in ΦPSII promoted the increase in maize biomass, ultimately leading to an increase in maize grain yield.

“In addition, NTG and TG significantly decreased the ST of maize from the big trumpet stage (V12) to the blister stage (R2), and the dissipation of excess energy (NPQ), compared with CT,” says Yu.

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Contact the author: 

Yulong Wang, E-mail: wyl1489270573@163.com;

Correspondence Aizhong Yu, Tel: +86-931-7603751, E-mail: yuaizh@gsau.edu.cn

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