Effect Of Different Planting Patterns On Soil Microbiological Characteristics And Crop In Gravel-sand Mulched Field

According to the problem of continuous cropping obstacles significantly and the lack of rotation patterns of the gravel-sand mulched field in the arid zone of central Ningxia, we designed four different rotation patterns included:watermelon�'ssunflower (T1), watermelon�'soybean (T2), watermelon�'pepper (T3), watermelon�'melon (T4) and four different intercropping patterns included: watermelon II sunflower (T5), watermelon II soybean (T6), watermelon II pepper (T7), watermelon II melon(T8) and with the continuous cropping of watermelon to be the same control (CK) to study soil microbiological characteristics, soil chemical properties, and crop physiological index. The main conclusions as follows:(1) Rotation and intercropping patterns significantly decreased the number and proportion of fungi, while significantly increased the number of bacteria and actinomyce, number ratio of B/F and A/F; proportion of bacteria and actinomyce were significantly higher than CK, proportion of fungi was significantly lower than CK; their microbial diversity index and evenness were obviously lower than CK. Rotation patterns effectively improved soil microbial community structure, then came the intercropping patterns, the effect of continuous cropping was the worst.(2) In the whole growth period of crops, SMBC, SMBN, soil respiration intensity and four enzyme activities first increased and then decreased under rotation and intercropping patterns, and they were higher than CK, T1,T2,T3and T5,T6,T7had significantly influence among them. Rotation patterns effectively improved soil microbial activities, then came the intercropping patterns, the effect of continuous cropping was the worst.(3) In the whole growth period of crops, soil temperature and pH increased, soil water content、 total salt and nutrient all first increased and then decreased under rotation and intercropping patterns. In the maturation stage, soil pH and total salt of all treatments were significantly lower than CK and T1decreased significantly; soil nutrition were higher than CK, T1,T2,T3and T5,T6,T7had significantly influence among them. Rotation patterns effectively decreased soil salinization and effectively improved soil available nutrition, then came the intercropping patterns, the effect of continuous cropping was the worst.(4) Under intercropping patterns, the LAI, SPAD, Fm, Fv, Fv/Fm and Fv/Fo of watermelon were higher than CK, Fo and Fo/Fm were lower than CK; the quality of watermelon were higher than CK, T5,T6,T7reached the high quality standard. Under rotation patterns, the economic benefit of crops were T4>CK>T3>T1>T2. Under intercropping patterns, the yield and economic benefit of watermelon were lower than CK, and CK>T7>T6>T5>T8; the economic benefit of intercropping crops were melon>pepper>sunflower>soybean; the LER of yield were T7>T6>T5、T8, the LER of economic benefit were T8>T5、T6>T7.