Effects Of Different Straw Incorporation Methods On Soil Fertility And Maize Growth

This study through two years of straw returned to locate experimental research under " separation modes" straw returned quantity(straw accounted for 0% of soil heavy, 0.44%, 0.88%, 0.44%) on the top layer of soil physical and chemical characteristic and the influence of maize growth, the nylon bag method in the field soil of different depth in situ training experimental study(0 ~ 15 cm, 15 to 30 cm, 30 ~ 45 cm) in different amount of straw(straw accounted for 0% of soil heavy, 0.44%, 0.88%, 1.32%, 2.64%, 5.28%) under the condition of soil humus composition and the dynamic change of soil enzyme activity, aims to explore suitable straw counters-field depth, appropriate amount of straw returned, provide theoretical basis for the straw counters-field enriching the soil.The results of the study are as follows:(1) " Separation modes", increased, straw returned arable layer gradually reduce soil bulk density and total porosity and soil water content increased gradually, compared with no straw returned, 1.32% amount of straw returned in 0 ~ 10 cm and 10 ~ 20 cm soil layer significantly reduced 8.25% and 11.36% respectively, and the soil bulk density of soil total porosity were significantly increased by 8.35%, 8.35%, soil water content significantly increased by 2.49% and 2.49% respectively;Straw returned to the mechanical stability of soil aggregate impact is not big, but significantly reduced < 0.01 mm graded and a significant increase in the 0.25 0.01 mm graded soil aggregate content, the soil characteristics of micro aggregate ratio decreased significantly, the soil micro aggregate of improvement.(2) "Separation modes" for two years increased the amount of straw returned, conducive to the accumulation of soil organic carbon, 1.32% amount of straw returned in 2013, 2014, two years of soil organic carbon content than straw counters-field increased by 7.40% and 7.40% respectively;With the increase of the amount of straw returned, the soil water soluble substances, soil humic acid and humin content increased;Returning straw returned two years later, the treatment can improve the soil of PQ value, 0.44% and 1.32% of PQ, a moderate increase in the volume straw returned, extending into the straw stalk rot in the soil solution time, can improve soil quality.Straw returned to soil WSS, HA, the molecular structure of the FA to develop in the direction of simplification, increase the amount of straw returned more conducive to WSS, FA molecular structure simplification, and the simplification has no obvious influence to the molecular structure of HA;Straw returned to increase soil catalase activity, soil urease, invertase activity increased with the increase of the amount of straw returned;Straw returned on maize root growth and development has a certain inhibitory effect, but the effect is not obvious, finally caused no corn production.(3)Soil of different depth by different amount of straw counters-field cultivation experiment in situ, straw returned can increase the content of different depth of soil organic carbon, the higher the amount of straw returned suitable scope.At the same depth WSS of soil organic carbon content increased with the increase of straw content, returning to deep soil is more beneficial to the improvement of the WSS soil organic carbon content;2.64%, 5.28%, straw content more conducive to the formation of 0 ~ 15 cm soil layer soil humic acid;Returning a depth of 15 ~ 30 cm and 30 ~ 45 cm, soil humic acid content increased with the increase of amount of straw returned to improve;Returning straw returned can increase the depth of soil humin content;The depth of soil layer of straw returned all can improve the soil catalase, urease and invertase activity.Overall, with the culture time, returning in the depth of soil catalase, urease, invertase enzyme activity with lower after rising first, develop time 0 ~ 15 cm, 15 to 30 cm, 30 ~ 45 cm soil layer soil catalase activity is highest, while building 90 d soil invertase activity high in 30 d.0 ~ 15 cm, 15 ~ 30 cm soil layer soil urease activity is highest, while building 30 d and 30 ~ 45 cm soil layer soil urease activity appeared in the 90 d.