Greenhouse gas emissions and drivers of the global warming potential of vineyards under different irrigation and fertilizer management practices

In the context of global warming and low water and fertilizer utilization efficiency in vineyards, identifying the driving factors of global warming potential (GWP) and proper irrigation and fertilization management strategies are crucial for high grape yields and emission reduction. In this experiment, drip fertigation technology was used, including three irrigation levels (W3 (100% M, where M is the irrigation quota), W2 (75% M) and W1 (50% M)) and four fertilization levels (F3 (648 kg hm-2), F2 (486 kg hm-2), F1 (324 kg hm-2) and F0 (0 kg hm-2)). Traditional furrow irrigation and fertilization (CG) and rainfed (CK) treatments were used as control treatments. The results indicated that under the drip fertigation system, fertilization significantly increased the grape leaf chlorophyll relative content (SPAD) and leaf area index (LAI) within a fertilizer application of 0-486 kg hm-2. Irrigation primarily had a direct positive effect on the water-filled pore space (WFPS) in the 0-60 cm soil layer, and the residual soil nutrient content was mainly affected by fertilization. The vital stage for reducing greenhouse gas emissions was the fruit-inflating and fruit-rendering stages. The CG treatment not only failed to ensure high grape yield but also adversely affected the soil environment and the reduction of greenhouse gas emissions in the vineyard. Fertilization had a direct positive effect on the grape SPAD, LAI, yield, and soil residual nutrient content. GWP was primarily directly driven by SPAD, WFPS, and soil residual nutrient content, while grape yield was primarily directly driven by fertilization and SPAD. In conclusion, the W2F2 treatment (25 % reduced irrigation and 486 kg hm-2 of fertilization) of drip fertigation in the vineyard was the preferred irrigation and fertilizer management strategy for maintaining good vine vigor and balancing grape yield and environmental benefits.