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Effects of Long-Term Continuous Cropping on Cotton Growth and on Cotton Field Soil Biological Activity

Author: ZhangWei
Tutor: LiuJianGuo
School: Shihezi University
Course: Crop Cultivation and Farming System
Keywords: Continuous cropping of cotton Soil biological activity Activated carbon treatment Straw
CLC: S562
Type: Master's thesis
Year: 2009
Downloads: 98
Quote: 0
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Abstract

Xinjiang is an important cash crops, cotton planting area, and even for a long time, resulting in a series of negative effects of continuous cropping of cotton in Xinjiang. The test through cotton long-term even for fixed-point micro-test study different even for years cotton biological amount, important physiological and biochemical indicators reveal even against the growth and yield of cotton; different continuous cropping Cotton Soil major soil microbial groups and soil enzyme activity sex change research and analysis, to explore the impact of continuous cropping of soil biological activity; activated carbon treatment and straw processing by comparing the continuous cropping Cotton Soil add cropping cotton field soil biological activity changes in to reveal straw cropping soil enzyme activities and activated carbon treatment the impact on soil biological activities. Reduce the continuous cropping obstacle for the production, establish a scientific cultivation system, Xinjiang cotton yield, high quality and sustainable production provides a theoretical basis. The main conclusions of the test are as follows: long-term even against the growth of cotton produce significant adverse effects, the Continuous Cropping processing part of cotton growth are subject to continuous cropping. Reduce the performance of cotton production; root activity, chlorophyll content increased with years of continuous cropping decreased with increasing the activity of SOD, POD activity and MDA content of roots and leaves increased to varying degrees in different growth stages. Adding activated carbon after SOD, POD activity and MDA content in contrast not add activated carbon to deal with different degrees of decline, root activity and chlorophyll content than without activated carbon treatment significantly improved. Related Physiological Indexes in the cotton growing process analysis shows that: cotton continuous cropping can cause harm to the growth and yield of cotton, adding activated carbon in the soil can reduce the adverse impact of the cotton due to continuous cropping obstacles. Cotton continuous cropping impact of changes in soil enzyme activities as cotton even years to increase the cotton fields of urease, invertase and catalase peroxidase activity reduced polyphenol oxidase activity showing the first decreased and then increased trend . Cropping Cotton Soil adding activated carbon, soil urease activity slightly higher than without activated carbon treatment, the the squaring stage 5 C, 10 C, 15 C, respectively, than without activated carbon treatment urease activity increased 11.4%, 7.2%, 0.3 %; invertase activity after adding activated carbon significantly improved, while the short-term even for the improvement effect is not obvious; catalase activity in continuous cropping increased after adding activated carbon, activated carbon treatment compared with the non-plus, activated carbon treatment over catalase activity was less affected, can not significantly improve soil conditions; polyphenol oxidase 5 C and 10 C than even for five years and even for a 10-year deal with the high activity of 15 C treatment compared with treatment for 15 years down . Adding activated carbon in the soil peroxidase activity is not obvious, does not significantly increase or decrease the peroxidase activity in the soil. Cotton even as to be able to reduce the average number of soil bacteria, the number of boll opening of bacteria with even for life extension first and then decreased, the short-term even as to be able to significantly reduce the number of bacteria in the soil, long-term even for the number of bacteria have increased by the trend; soil fungi in the average number of trends first and then decreased, even for a five-year deal with the lowest number of fungi, in cropping soil treatment in 15 years, the highest number of fungi; increased the average number of actinomycetes trend of reduced reduced, even for a five-year deal with the lowest number, the actinomycetes highest 10-year deal with the continuous cropping. The number of bacteria in the activated carbon in the soil decreased in the seedling stage, maternity late addition to the long-term continuous cropping, soil, activated carbon can significantly increase the number of bacteria in the soil. Different growth period of the cropping reduced the number of bacteria in the life of the soil increased first and then presented with the growth trend. Adding activated carbon number of fungi in the late growth stage can significantly reduce the number of fungi in the soil, to reduce cotton caused by the fungus continuous cropping. Number of fungi in the whole growth period of the highest in the seedling stage, squaring reduce, flowering rose again, the lowest number of fungi in the soil of the boll opening stage. No regular changes of soil actinomycetes activated carbon. Cotton fields to implement straw, soil urease activity with the extension of the continuous cropping first decreased and increased, not more than 15 years of continuous cropping, soil urease activity downward trend, have increased by more than 15 years; invertase activity in continuous cropping 10-year activity minimum, long-term even for the sucrose enzyme activity enhanced, soil conditions tends to improve, there is conducive to the growth and development of cotton; too catalase activity with even for the prolongation of the first reduced and increased, short-term even as the soil over the catalase activity than the low, the decomposition of hydrogen peroxide blocked, affecting cotton growth, continuous cropping over more than 10 years increased catalase activity, detoxification ability, speed up the decomposition of hydrogen peroxide will help reduce the toxic effects of hydrogen peroxide soil and biological; straw processing with the extension of the continuous cropping, the peroxidase activity is on the rise.

Effects of Long-Term Continuous Cropping on Cotton Growth and on Cotton Field Soil Biological Activity

Abstract

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