Responses Of Soil Fertility To Soil Conditioner And Microbial Inoculum In Continuous Cropping And Gravel Mulch Field For Watermelon Cultivation

In order to solve the problems of soil fertility and the decline of plant growth,yield and fruit quality of sand compacted watermelon in Ningxia,based on local conventional fertilization methods,organic fertilizers were combined with soil conditioners and fungi to fertilize the soil to promote plant growth Development,increase yield and improve the quality of pressed sandmelon.In this study,the sandstone watermelon "glory" was used as the experimental material,a field plot experiment was conducted to explore the effects of different soil conditioners and soil conditioners combined with bacterial agents on soil physical,chemical and biological properties,stem diameter,root activity,yield and quality of sand watermelon.It is of great significance to improve soil fertility,increase crop yield and promote economic benefit in local continuous cropping sand watermelon field.The main test results are as follows:The application of soil conditioner is beneficial to the regulation of soil physical properties of 0-40 cm soil layer in continuous cropping sandmelon field.Among them,the application of soil conditioner could significantly improve the physical properties of the 0-20 cm soil layer.Compared with local conventional fertilization treatment,soil water content,field water holding capacity and porosity increased by 8.31%-29.19%,40.82%-87.81%,6.14%-9.27%,respectively,and the bulk density decreased by 5.84%-8.76%.It showed that the soil conditioner played a significant role in improving soil water content,field water holding capacity,porosity and bulk density.However,the single application of bacteria did not significantly improve the physical properties of the soil.Compared with conventional fertilization and soil conditioner combined with bacterial agent,the application of soil conditioner could improve the soil chemical properties.This study indicated that the mass fraction of soil nutrients tended to increase first and then decreased with the growth period of pressed sandmelon.However,compared with conventional fertilization treatment and soil conditioner combined with bacterial agent treatment,the app.lication of soil conditioner could significantly reduce soil pH value and total salt content,and improve the mass fraction of soil available nutrients and available nutrients,and the effect was more significant in the later stage of sand watermelon growth.The application of soil conditioner,soil conditioner combined with bacterial agent could improve soil biological properties.This study revealed that conventional fertilization+soil conditioner A 150 kg·hm-2+soil conditioner B 150 kg·hm-2+fungus treatment has the best effect,in which the catalase and alkali in the 0-20 cm soil layer at maturity The activities of sex phosphatase,urease and sucrase were increased by 10.05%,103.57%,164.86%and 12.35%respectively compared with conventional fertilization.The number of bacteria,actinomycetes and fungi were increased by 225.00%,49.21%and 67.83%,respectively,which provided a good micro-ecological environment for the growth and development of sand watermelon,and had a significant effect on the growth of sand watermelon in the later stage.Increasing the application of soil conditioner soil conditioner combined with bacterial agent could significantly improve the growth and quality of pressed sandmelon Among them,the conventional fertilization+soil conditioner A 150 kg·hm-2+soil conditioner B 150 kg·hm-2 treatment of pressed sandmelon fruit vitamin C mass fraction was 106.79 mg·kg-1,soluble solids mass fraction was 12.64%,which was 52.79%and 20.27%higher than that of conventional fertilization treatment,respectively.Conventional fertilization+soil conditioner A 150 kg·hm2+soil conditioner B 150 kg·hm-2+fungicide treatment Pressed watermelon fruit Vitamin C mass fraction was 115.21 mg·kg-1,soluble solids mass fraction was 13.11%,respectively,compared with conventional fertilization treatment increased by 67.79%,24.64%;increased by 51.46%and 22.89%respectively compared with the single fertilizer treatment The results displayed that the soil conditioner combined with the bacterial fertilizer could improve the quality of the sand pressed watermelon compared with the conventional fertilization and single bacterial agent.Person bivariate correlation analysis showed that the physical and chemical properties and biological properties of compacted sand soil were significantly correlated with the growth,yield and quality of watermelon.The calculation results of the Nemero index method indicated that the conventional fertilization+soil conditioner A 150 kg·hm-2+soil conditioner B 150 kg·hm-2+fungicide treatment had the highest comprehensive fertility index(0.9186),which was higher than conventional fertilization Increased by 25.12%;its output reached 45173.70 kg·hm-2,and its net income reached 19034.70 Yuan·hm-2.The net income increased by 54.43%compared with conventional fertilization.Comprehensively comparing the yield,economic benefit,and comprehensive soil fertility index of each treatment,the best treatment is recommended as M3:conventional fertilization+soil conditioner A 150 kg·hm-2+soil conditioner B 150 kg·hm-2+fungicide.