| Vegetables are one of the basic sources of human food,rich in nutrients such as vitamins,dietary fiber,and minerals,which are important for human health.The vegetable industry in the Southwest region of China has experienced rapid growth in recent years,the vegetable industry in the Southwest region of China has developed rapidly,and as of 2021,the vegetable planting area and total output respectively accounted for 23.2% and 17.2% of the national vegetable planting area and total output(China Rural Statistical Yearbook,2022).In intensive vegetable production in the Southwest region,excessive fertilizer application by farmers to achieve higher yields has led to a series of more serious problems including the accumulation of nitrogen,phosphorus,and potassium nutrients in soil and the acidification of soil,which in turn affect vegetable yields and quality.Currently,organic-inorganic compound fertilization is an effective measure to improve soil quality and increase vegetable yield and quality(Li Yanqing et al.,2019).However,the research on the application effects of organic fertilizers mainly focuses on grain crop systems(Ryan et al.,2004;Gabriel et al.,2013;Campiglia et al.,2014),and relatively few studies have been conducted on vegetable crops.Therefore,this study first used the method of integrated data analysis to comprehensively quantify the impact of organic management measures on vegetable production yield and quality in different regions and reveal the effects of different field management measures.Second,taking chili peppers as the research object,a combination of pot experiments and root box experiments was used to explore the effects of organicinorganic compound fertilizers on soil physical and chemical properties,crop yield,quality,and nitrogen fertilizer utilization efficiency,three compost materials containing varying ratios of livestock and poultry manure,biochar,and kitchen waste were utilized.The study selected the best materials and proportions suitable for their growth,created vegetable-specific organic-inorganic compound fertilizers,and explored their mechanisms for increasing vegetable yield and evaluating their application effects,in order to provide theoretical foundation for guiding the resource usage of agricultural waste and the production of vegetable-specific organic-inorganic compound fertilizers.The main results are as follows:1.Our results showed that organic agriculture could decrease vegetable yields(-14.5%),significantly increase vegetable Vitamin C(Vc)content(34.8%)and soluble sugar content(39.5%),but significantly decrease nitrate content(-32.2%).Organic agriculture increased soluble sugar(46.3%)under open-field cultivation,which were higher than those under the conditions of greenhouse,and the yield difference was not significant between them.Compared with other vegetable types,organic agriculture had the highest effect on decreasing the yield(-23.9%),nitrate content(-34.3%)and increasing soluble sugar content(53.9%)for leafy vegetables.Under different application amounts of nitrogen conditions,when application amounts of nitrogen were more than 250 kg ha–1,organic agriculture had the highest effect on increasing vegetable yield(4.9%)and Vc content(33.2%).Compared to other regions,North America had the lowest yield reduction of 11.4%.Principal component analysis(PCA)showed that soil total nitrogen content and organic matter content were the main factors in promoting the increase of vegetable yields under organic agriculture,while soil available potassium content and soil pH were the main factors in promoting the increase of vegetable quality.2.Our results showed that compared with the control group(CK)without fertilization,different combinations of organic and inorganic fertilizers significantly increased the chili pepper yield by 7.3% to 41.7%,decreased the nitrate content by 3.0% to 37.4%,and increased the accumulation of nitrogen,phosphorus,and potassium by 94.4% to 151.8%,2.1% to 38.8%,and 154.9% to 304.7%,respectively,as well as the soil nutrient content.Compared with the group that only received chemical fertilizer(T1),the different combinations of organic and inorganic fertilizers increased the soil alkali nitrogen content by 3.1% to 33.5%.There was no significant difference in yield,stem thickness,plant height,and SPAD value among the different fertilization treatments.The nitrate content of chili pepper(35.3 mg kg-1)and the accumulation of nitrogen(29.2 g pot-1),phosphorus(2.6 g pot-1),and potassium(27.7 g pot-1)were the highest in the group that only received chemical fertilizer(T1);among the different combinations of organic and inorganic fertilizers using different raw materials and ratios,there was no significant difference in stem thickness,plant height,SPAD value,nitrogen,phosphorus,and potassium concentration,and nitrogen and phosphorus absorption.Among them,the combination of 1/3 food waste and organic-inorganic fertilizer(T4)had the highest yield(23.8 g pot-1),soil alkali nitrogen content(41.2 mg kg-1),and the greatest decrease in nitrate content(37.4%)and soil p H value(10.2%),indicating that the comprehensive application effect of the treatment using 1/3 food waste instead of chemical fertilizer(T4)was superior to other combinations of organic and inorganic fertilizers in terms of yield,quality,and soil physicochemical properties.3.Our results showed that compared with the unfertilized(CK)treatment,the vegetable-specific organic-inorganic compound fertilizer significantly increased the stem dry weight,leaf dry weight,and root dry weight of chili by 142.8% to 164.3%,131.3% to 150.0%,and 54.0% to 85.7%,respectively.Fertilization effectively increased the aboveground nitrogen,phosphorus,and potassium concentrations,but decreased the root nitrogen,phosphorus,and potassium concentrations,increased soil nutrient content,and significantly lowered soil p H.There was no significant difference in SPAD values,nitrogen,phosphorus,and potassium accumulation among the fertilization treatments.Compared with single chemical fertilizer application,the vegetablespecific organic-inorganic compound fertilizer treatment significantly increased the soil organic matter content.Under different fertilization methods,uniform application of chili with the vegetable-specific organic-inorganic compound fertilizer(Y3)significantly increased plant height compared with row application,and this treatment also had the highest stem diameter(5.1 mm)and plant height(54.0 cm),as well as the highest nitrogen and phosphorus accumulation in roots and leaves.The indicators of chili root system and soil organic matter content in different soil layers were significantly higher in the uniform application of vegetable-specific organicinorganic compound fertilizer(Y3)than in the row application of vegetable-specific organicinorganic compound fertilizer(Y4)in the 5-10 cm soil layer.In conclusion,the comprehensive application of vegetable-specific organic-inorganic compound fertilizer is superior to single chemical fertilizer treatment,and uniform application(Y3)has a better comprehensive effect on yield,nutrient accumulation,root morphology,and soil physicochemical properties than row application(Y4). |
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