Effects Of Tillage Methods On Double Cropping Machine-transplanted Rice Growth And Soil Physical And Chemical Properties

In measures for agricultural production, how to use reasonable tillage methods is an important research subject in the field of agriculture conservation tillage.To explore the influence of different tillage methods on rice growth and soil physical and chemical properties, 2 years big field positioning test was conducted during 2013-2014.Under the condition of equal NPK nutrient application, the effects of mechanized rotary tillage, conventional cross tillage(oxen-led), alternate years of mechanized rotary tillage and Conventional cross tillage on soil physical and chemical properties,growth and yield of double-season rice were studied to clarify the influence of different tillage methods on growth and development of double season rice and soil fertility. The main research results were as follows:1.The effects of tillage methods on rice growthAfter 2 years location test, there was no significant difference on yield of early and late rice, effective panicle, the total number of particles, seed-setting rate and 1000-grain weight between the three of the oxen-led, rotary tillage, oxen-led alternating with rotary year cultivations, which showed that different cultivations had less influence on the yield of double-season rice.Oxen-led treatment improved the tillering rate, spike rate and leaf area index(LAI) during later development stages of early rice; The alternating treatment between oxen-led and rotary tillage every other year was in favor of improving the tillering rate, spike rate of late rice, but not conducive to improve the leaf area index in middle and later stages. There was no obvious regularity on dry matter translocation between the three treatments, but oxen-led treatment helped to improve the output rate, conversion and contribution rate of the late rice dry matter.After heading stage, the SPAD value of flag leaf of early rice under oxen-led treatment was higher than oxen-led alternating with rotary tillage as well as rotary tillage; However, for late rice, oxen-led alternating with rotary treatment every other year was higher than oxen-led, rotary tillage treatments.0 ~ 10 cm soil root dry weight was significantly higher than that in 10 ~ 20 cm soil layer in cultivated horizon, but no significant difference existed at the same cropping soil layer between the three treatments, total root weight in two years had the same trends : it was heavier under oxen-led treatment than the other treatments.Rotary tillage treatment is helpful for early rice plant nitrogen accumulation, whereas oxen-led treatment is beneficial to the accumulation of phosphorus and potassium.2.The effect of tillage methods on soil physicochemical propertiesThe soil bulk density, total porosity and capillary porosity of the same layers under different tillage methods had little difference, but all increased with soil depth; 15 ~ 30 cm oxen-led treatment significantly lower than that of continuous rotary tillage soil bulk density, but the total porosity and capillary porosity and porosity of ventilation on the contrary, which showed that continuous rotary tillage can lead to soil hardening under cultivated horizon. The alternating treatments between rotary tillage and oxen-led helped to change the adverse effects on soil physical properties of continuous tillage.Soil nutrient content in 0 ~ 10 cm layer was significantly higher than that in 10 ~ 20 cm soil layer. The early rice in the second year compared to the first year, organic matter, available nitrogen and phosphorus of soil have declined, but the total nitrogen, potassium increased. Late rice in the second year, organic matter, available K increased, available nitrogen, phosphorus decreased, but the total nitrogen changed little.Soil organic carbon, mineralization carbon, steady-state carbon content decreased, but activated carbon content increased in 0 ~ 10 cm soil layer. The late rice 10 ~ 20 cm soil layer, soil organic carbon, mineralization carbon, steady-state carbon, activated carbon all has fallen.Two years experiment showed that, compared to oxen-led, rotary tillage treatment would gradually improve the soil enzyme activities, the effect on oxen-led alternating with rotary cultivation every other year is obvious in early rice.