Effects of water and nitrogen regulation on growth,yield and quality of tomato in substrate-amended gravel-mulched soils
Zhao Wenju
Yin Jianxiang
Zhou Changquan
Wang Zhijun
Li Jiancheng
Ma Hong
Abstract：[Objective]Gravel-mulched farmlands are characterized by poor soil structure,low nutrient retention and inefficient water and nitrogen use.To address these issues,this paper studied the efficacy of amending the soils with recycled agricultural wastes in improving crop drought resistance and promoting crop growth in such soils.[Method]The experiment was conducted in a greenhouse,with the soil amended with a mixture of compost and crop straws.Nine treatments were set up by combining three irrigation levels:irrigating 100%(W1),80%(W2),and 60%(W3)of crop evapotranspiration;and three nitrogen application levels:applying 240 kg/hm2(N1),204 kg/hm2(N2)and 168 kg/hm2(N3)of nitrogen fertilizer.The control was the conventional water and nitrogen management without soil amendment(CK)as used by local farmers.Fruit quality,yield,water use efficiency(WUE),and nitrogen partial factor productivity(NPFP)of the crop were measured to establish a comprehensive evaluation system.A multi-objective optimization model was established and solved using a genetic algorithm to obtain the Pareto optimal solution set.[Result]①Irrigation and nitrogen fertilization significantly affected tomato growth(P＜0.05).②Compared with CK,soil amendment considerably increased plant height,stem diameter,individual total dry matter accumulation,root mass,total root length,and total root surface area of the tomato plants by 4.87%～13.30%、5.18%～25.70%、0.16%～37.11%、2.95%～42.74%、1.56%～31.37%、1.42%～18.39%,respectively.These improvements in turn promoted tomato yield formation.W2N2 was the optimal irrigation and nitrogen fertilization regime for tomato in gravel-mulched soils.③Under the W2N2 treatment,the tomato yield reached 36 150 kg/hm2,WUE was 17.89 kg/m3,NPFP was 117.24 kg/kg,and the fruit sugar-acid ratio was 10.22.[Conclusion]Amending the soil with a mixture of compost and crop straws,combined with irrigation at 80%of crop evapotranspiration and nitrogen fertilization at 204 kg/hm2,is optimal for improving water and fertilizer use efficiency while maintaining a balanced yield and fruit quality of greenhouse tomatoes in the study region.
Keywords：gravel landsubstrate cultivationwater and nitrogen interactiontomatogenetic algorithm
Publication Date：2026-08-31
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：8( 1-8 )