Abstract:

To elucidate the intrinsic mechanisms underlying the amelioration of degraded black soils by organic fertilizers,and thereby provide a scientific basis for optimizing chemical fertilizer reduction strategies while safeguarding long-term soil productivity in the target region,a maize field trial was conducted in 2024.Six fertilization treatments were established,as follows:CF(regular fertilization),RF(20% reduction of chemical fertilizer),RFH1(RF supplemented with 200 kg/ha humic acid fertilizer),RFH2(RF supplemented with 330 kg/ha humic acid fertilizer),RFO1(RF supplemented with 200 kg/ha chicken manure organic fertilizer)and RFO2(RF supplemented with 330 kg/ha chicken manure organic fertilizer).Compared to CF and RF,the RFH2,RFO1,and RFO2 treatments significantly reduced soil bulk density by 12.4%—20.7%.All organic amendment treatments improved soil structure stability,and the fraction of water-stable aggregates(>0.25 mm)increased by 15.9%—39.1%,while soil pH decreased by 0.8%—1.2%.RFO1 and RFO2 elevated soil alkaline hydrolyzable nitrogen content by 14.6%—28.5%.Additionally,every organic treatment increased soil available phosphorus and soil organic matter contents by 8.7%—36.8% and 11.0%—48.9%,respectively,with RFO2 showing the most pronounced improvements.At the same time,RFH2,RFO1,and RFO2 significantly enhanced the activities of key soil enzymes(urease,amylase,catalase,alkaline phosphatase,and sucrase)by 18.1%—72.4%.In terms of grain yield,RFH2,RFO1,and RFO2 outperformed CF by 0.5%—13.9%,and all organic amended treatments increased by 16.7%—36.6% compared with RF,with RFO2 achieving the highest yield.Organic amended treatments also improved partial productivity and agronomic efficiency of fertilizers by 11.9%—31.1%,while RFO2 exhibited 25.8%—36.6% higher nitrogen and phosphorus partial productivity compared to CF and RF.Overall,chemical fertilizer reduction combined with organic fertilizer effectively improved soil physicochemical properties,enhanced soil enzyme activities,and increased nutrient-use efficiency.This practice not only maintained maize yield but also contributed to the restoration of degraded black soils.Thus,20% chemical fertilizer reduction combined with 330 kg/ha chicken manure organic fertilizer(RFO2)was identified as the optimal fertilization strategy for degraded black soils in this experiment.

Key words: Maize, Degraded black soil, Chemical fertilizer reduction, Organic fertilizer application, Soil physicochemical properties, Yield

CLC Number: 

• S158.3

• S513玉米(玉蜀黍)