Effects Of Water And Fertilizer Management On Soil Environment And Tomato Growth In Solar-greenhouse

The research was conducted to study the effects of fertilization, soil conditioner and straw counters-field on soil ecological factors such as soil temperature, humidity, microorganism, enzyme activity and chemical properties, tomato plant growth, tomato yield, water productivity, N partial factor production and economic benefit under the conditions of different irrigation (drip irrigation and furrow irrigation under membrane) in Solar-greenhouse. The study results showed that:(1) The effect of water and fertilizer management on soil temperature was not significant in Solar-greenhouse. Straw could only increase soil temperature by0.2℃. The effect of the drip was much less than the role of influencing indoor temperature in the external environment. Compared with furrow irrigation, drip irrigation treatment could reduce irrigation quantity, infiltration quantity and water consume, and the effect was slight to soil water suction at40cm depth of soil. In early stage, because of the low soil temperature, water suction changes slight, the upper limitation of water suction was controlled at40KPa, but in late stage, owing to the rise of the temperature, transpiration intense, soil water suction changes greatly, the upper limitation of water suction was controlled at60KPa.(2) In the whole period of tomato growth, the trends of soil microorganism quantity, the number of bacteria, the bacteria and fungi ratios (B/F) firstly decreased, then increased and decreased again at last, the number of fungi and actinomycetes was decreased and then gradually increased. The activity of cellulose enzyme in soil was gradually decline, the trends of catalase activity was firstly decreased, but then increased and decreased at last. Cellulose decomposition microbes all appeared a peak in the treatment of adding straw in soil. In the low temperature period, the microbial number in the treatment of drip irrigation or adding straw was higher than other treatments. Soil microorganism quantity and plant growth of drip irrigation treatment was delayed compared with other treatments. FP +M+C treatment early provided lots of carbon that lead to microbial number increased, but later microbial number was less. Catalase activity was higher at drip irrigation than at furrow irrigation under membrane, adding straw could improve the cellulose enzyme activity in early stage, and increase the number of fungi and actinomycetes.(3) Research results showed that the NO3--N mainly accumulated in the soil surface and below80cm depth in the soil profile, the content of NO3--N was the lowest in the20to40cm depth, the content of NO3--N was higher in furrow irrigation than in drip irrigation under membrane in the cumulative layers. Drip irrigation improved the soil pH value and reduced the soil EC value. The pH of the FG+HM+S treatment was the highest, whereas the EC of FG+HM+C treatment was the lowest. The contents of total soil nitrogen, available P, available K and organic matter all appeared:FG+M> FP+M, there were a significant correlation between the soil nutrients. The soil pH, EC showed linear correlation with NO3-N, the R2value was0.88and0.93respectively.(4)The height of plant and the number of leaf of the FP+M treatment was the largest, but stem diameter was less than FG+M treatment. Tomato’s yield of FG+M treatment was the highest, it was increased by19.89%, compared with FP+M treatment. Water productivity and N partial factor production was much higher in fertigation than in furrow irrigation under membrane, and water productivity of FG+M was the highest,1.6times of FP+M. N partial factor production of FG+HM+S was the highest,2.6times of FP+M. The relative net output value of FG+M treatment was284.2thousand yuan per hectare, FG+M was nearly60thousand yuan per hectare higher than FP+M treatment.