Effect Of Topsoil Thickening And Fertilize Mechanism In Facility Vegetable Field

Facilities in successive planting are prone to continuous cropping obstacle, such as cultivate layer getting thinner, nutrient uneven distribution, microbial regional imbalance, insect pest. In order to overcome the soil physical and chemical properties of thin, deterioration, a experiment set up two tillage (surface tillage, deep tillage) and three fertilization mode (no fertilizer, organic fertilizer, organic fertilizer and straw). It mainly researched effects of different tillage, fertilization on soil physicochemical properties. It was arranged in Beijing suburb, which used the ways of a field experiment and indoor analysis. The selected crops were cauliflower and fresh corn in the experiment. It mainly studied these measures on soil physical and chemical properties, biological characteristics and crop growth aspect. These measures included deep plowing, organic fertilizer and straw mulching. The results showed as follows:1Plowing and fertilization improved the soil physical character. After deep plowing or applying the organic fertilizer and straw, soil bulk density effectively reduced, soil water content increased, the soil bulk density of15～30cm was reduced significantly by0.141g/cm3under the treatment of deep plowing and applying organic fertilizer and straw. Applying organic fertilizer or straw can effectively reduce the soil temperature of0-30cm, soil temperature decreased by2～4centigrade in12:00, increased by3～4centigrade in18:00. The proportions of soil mechanical composition showed different change trend under different fertilization. Applying organic fertilizer and straw can make micro granular structure of0.05mm-0.25mm reached to44.32%and42.93%, applying organic fertilizer was lower, no fertilizer treatment was the lowest, only38.88%and38.82%.2Fertilization improved the soil nutrient content. After different fertilization treatment, soil nutrient content of the soil layer of0～15cm was higher than the soil layer of15～30cm, and the change trend is same. Applying organic fertilizer or straw was helpful to increase soil organic matter and total nitrogen content, which made the organic matter content of the soil layer of0～15cm increased by7.15g/kg and5.93g/kg, while made soil total nitrogen content of the soil layer of15-30cm increased by0.57g/kg and0.70g/kg. Fertilization can increase soil inorganic nitrogen, available phosphorus and potassium. In the soil layer of0-15cm, content of soil inorganic nitrogen increased by28.55～39.21mg/kg; available phosphorus increased by9.66～29.19mg/kg, available potassium increased by38.33-143.59mg/kg.3Fertilization improved the soil biological character. Application of organic and straw returned to field was helpful for increasing the number of soil earthworms, microbial quantity and microbial carbon content. After applying organic fertilizer and straw, soil earthworms number achieved above30per square meter, equivalent to three times the blank processing. Application of organic fertilizer and straw processing, the number of bacteria increased1.75×107/g, the number of actinomycetes increased3.93×106/g and the number of fungi increased2.47×104/g, the microbial carbon content of two soil layers was increased by44.82mg/kg and31.82mg/kg.4Organic fertilizer and straw joined can promote crop growth, increase crop yields. Compared with the blank control, fertilization increased the root distribution in two layers, so that biological yield of three stubble crop had been enhanced. Of these, the growth rate is13.61%～37.69%in romanesco growing season,20.89%～70.1%in cauliflower growing season, while3.84%～12.98%in fresh corn growing season. And the economic yield also had rise certainly, but the difference was not significant. At the same time, applying fertilization and straw made vitamin C of romanesco and broccoli increased respectively by53.19mg/kg and74.30mg/kg. The nitrate content of cauliflower reduced by49.42～50.40mg/kg after deep tillage.5The treatment of straw returned to field on basis of organic fertilizer can increase the seasonal utilization rate of nitrogen, phosphate, and potash. The nitrogen utilization rate was increased by0.11～10.00percentage points, phosphorus utilization rate was increased by1.40～8.96percentage points, potassium utilization rate was increased by14.20～35.19percentage points. Through the calculation of the apparent nutrient balance in soil-crop system, straw can also reduce the apparent loss of nitrogen by89.03kg/ha and the apparent loss of phosphorus by105.93kg/ha.