Effects Of Applying Biogas Fertilizer On Soil Character Of Conservation Field And Crop Yield And Quality

Aimed at effects of biogas fertilizer different applying content and ratio on agronomic character, yield, nutrient quality of eatable part of fruits, nitrate and content of heavy metal in tomato and watermelon in the yellow river irrigation area. The residual content of heavy metal Pb, As, Hg in biogas fertilizer and soil, in order to provide basic datum in effective guide and extend using of biogas fertilizer in local area production and afford science evidence for production of green vegetables and fruits of lower nitrate and higher nutrients quality to choosing high quality fertilizer and optimizing combination of applying fertilizer. The results shows:(1) Biogas fertilizer graded test during tomato sowing, found when its applying content were controlled on52500kg-hm-2(normal content), guarantee effectively soil organic matter and nutrient content, when content were too low, can not alter effectively soil fertility. Soil microorganism C,N,P were increasing with more using of biogas fertilizer, in fruiting early phase and harvest time, soil microorganism C,N,P were increasing fast, when using was52500kg-hm"2, soil microorganism C present a great increasing, when67500kg·hm-2,increasing slow, but microorganism N,P were always increasing trend with adding of fertilizer. Before tomato sowing and after harvest, Pb,As,Hg content of soil reach "soil environment quality standards" the state demanding, but after harvest, their content in soil were increasing with more use of biogas fertilizer, when using content were52500kg-hm"2(T4), soil content was equal to soil that before sowing, when using continue to increasing, Pb,As,Hg content of soil were higher than original content of soil before sowing, especially, soil Hg content increasing range were bigger.(2) Topdressing biogas fertilizer played a positive impact on plant growing and developing, grain number of single plant, ratio of grain mature, quality of single grain and yield in traditional planting of tamato, when using was52500kg-hm"2, yield reached highest, compared with CK increasing by86.0%. Picking grains in all kinds of period, their Vc, solubility total sugar content presented increasing first, then decreasing trend with using adding of fertilizer. But grain nitrate content kept on increasing too, especial, when adding to67500kg-hm"2, increasing rapidly, when adding to75000kg-hm"2, content was up to the highest,307.22mg·kg-1. Pb,As,Hg content of tomato grain were increasing clearly with adding of biogas fertilizer, increasing range of Hg were the biggest, T7treatment, content were up to the highest,0.9452μg-kg-1.(3) In the watermelon experiment, soil Pb,As,Hg content in every treatment were higher than unused fertilizer treatment, Pb,As content relatively higher, Hg relatively lower. Soil heavy metal of applying biogas fertilizer were higher than that of other applying fertilizer treatments.(4) Basic biogas fertilizer combined with topdressing chemical fertilizer and biogas fertilizer can reached increasing yield obviously, compare with CK, T9treatment increasing by93.7%. Each treatment of using fertilizer, Vc, solubility total sugar content in treatment were increasing marked than that in CK, yet Vc, solubility total sugar in the treatment to using biogas fertilizer were more increasing than that in the treatment to unused biogas, Vc, solubility total sugar in T9treatment of basic biogas and topdressing chemical, biogas, were up to the highest, respectively8.62mg·kg-1,7.72%. The nitrate content of basic fertilizer decreased obviously than that of basic stable fertilizer and basic chemical fertilizer, eatable part nitrate content of chemical fertilizer combined biogas fertilizer were lower significantly than that of stable fertilizer combined chemical fertilizer. Different using fertilizer treatment had a marked different impact on Pb,As,Hg content in the eatable part of watermelon. The content of Pb,As,Hg in the eatable part of watermelon in all the using biogas fertilizer-treatments presented marked lower than unused fertilizer treatment.