Relationship between agricultural water and soil resources carrying capacity and crop yield with long-term plastic film mulching coupled with fertilization

Context

The black soil area located in northeast China is one of the four major black soil areas in the world, with developed agriculture. Due to the long-term intensive utilization of cultivated land and low nutrient input, the deterioration of soil and water resources in cultivated land is accelerated, which challenges the carrying capacity of cultivated land and water resources for grain production. However, the impact of the carrying capacity of land and water resources on grain production at field scale is still unclear. This is crucial for optimizing tillage measures to promote the steady improvement of the carrying capacity of cultivated land and water resources for food production.

Objective

Utilizing a 37-year long-term field positioning experiment, this study quantitatively evaluated the agricultural water and soil resources carrying capacity index (WSI) under varying mulching and fertilization regimes and established their functional correlations with maize yield dynamics.

Methods

Based on the 37 year continuous mulching and fertilization experiment of brown earth at Shenyang Agricultural University, 14 treatments were selected, including single application of nitrogen fertilizer (N₂, N₄), single application of organic fertilizer (M₂, M₄), organic fertilizer+nitrogen fertilizer (M₁N₁, M₂N₂), and no fertilization (CK), under mulching (F) and non mulching (WF) conditions.

Results

The results showed that both mulching and fertilization can significantly improve the WSI and crop yield. Among them, the treatment of mulching with high organic fertilizer and nitrogen fertilizer (FM₂N₂) had the most significant effect on both carrying capacity and yield of agricultural water and soil resources. For every 0.1 unit increase in the WSI, the yield of corn under mulching and non mulching conditions can increase by 11.8 % and 12.01 %, respectively. Under mulching conditions, the average yields of N₂, N₄, M₂, M₄, M₁N₁, and M₂N₂ treatments increased by 43.91 %, 71.3 %, 62.84 %, 97.38 %, 68.58 %, and 85.3 %, respectively. The WSI increased by 6.61 %, 7.47 %, 16.97 %, 20.29 %, 18.83 %, and 22.6 %, respectively; Under non mulching conditions, the average yields of N₂, N₄, M₂, M₄, M₁N₁, and M₂N₂ treatments increased by 48.1 %, 65.5 %, 97.79 %, 134.72 %, 120.55 %, and 122.32 %, respectively. The WSI increased by 4.07 %, 5.58 %, 13.63 %, 18.29 %, 16.78 %, and 20.31 %, respectively. Overall, except for the CK treatment, the WSI of the mulching fertilization treatment was higher than that of the non mulching fertilization treatment.

Conclusions

Under long-term high-intensity intensive management conditions, film mulching, single application of organic fertilizer (FM₄), and combination application of film mulching organic fertilizer and nitrogen fertilizer (FM₂N₂) are effective ways to achieve dual improvement of agricultural water and soil resource carrying capacity and crop yield.

Implications

The research results can provide theoretical guidance and technical path implementation references for the dual improvement of agricultural water and soil resource carrying capacity and grain yield in Northeast China cultivated land.