Several Cropping Systems’ Comprehensive Benefit Under Different Waterlogging Conditions

The middle reach of Yangtze river is located in the subtropical monsoon climate zone, waterlogged disaster is serious due to the influence of various factors and restriction in this area. In view of this, with the support of nonprofit sector (agriculture) research projects " key technology research and demonstration of the waterlogged disaster prevention and control of major crops "(201203032), We test comprehensive effect of several cropping system on different waterlogged conditions from2012to2013in the Yangtze river university campus test base. We set up different cropping systems under general water disaster, generous waterlogging, Serious waterlogging three processing, cole-watermelon and corn, Rice shrimp mixed cropping pattern, rape-job’s-tears compared with traditional model of "oil and rice" under same conditions. We tested physiological index and economic benefit, ecological benefit and social benefit under different waterlogged conditions. In order to enhance the capacity of the region around and realize the sustainable development of agriculture to provide theoretical basis and technical support. The results show that:1)In terms of physiological indexes, there was no significant difference between four kinds of physiological indexes of two modes under general waterlogging; Under the general water disaster, MDA, CAT and POD and chlorophyll content were significantly different; Under serious waterlogging, MDA, CAT and POD were significantly different, chlorophyll was no difference. Watermelon has no better adaptability than rice under general water disaster; two modes of general waterlogging had same adaptability almost; In the serious waterlogging job’s-tears has better adaptability than rice.2) In terms of economic efficiency, under general water disaster,"cole-watermelon and corn" mode compared with the traditional model of "oil and rice". ratio of input and output in two years were1:2.57,1:2.49and1:3.91,1:2.96, profits were higher16times and13times than the conventional model respectively.Under condition of general waterlogging;"Rice shrimp mixed cropping pattern compared with the traditional pattern of "oil-rice ", ratio of input and output in two years were1:4.58,1:2.39and1:3.71,1:2.85respectively, profits were higher4times and3times than conventional mode.Under condition of serious waterlogging."rape-job’s-tears" model compared with the traditional pattern of "oil-rice", ratio of input and output in two years were1:2.68,1:2.31and1:1.38,1:1.75respectively, profits higher3times and1.7times than conventional mode respectively.In terms of economic benefit, calculation of the economic data such as general input and output under three kinds new planting system compared with traditional mode, they can greatly improve the efficiency of the output per unit area. General water disaster>General waterlogging> Serious waterlogging.3) In terms of ecological benefits,6indicators (nitrate nitrogen, ammonium nitrogen, orthophosphoric acid salt, total nitrogen, total phosphorus, total phosphorus) of water quality under the condition of general waterlogging had no significant difference. Result shows that under the premise of no fertilizer application rice shrimp mixed cropping patterns in the later, rice and shrimp could normal grow, and water quality had no obvious change, thus rice shrimp intercropping mode has a certain ecological benefits.The cumulative emissions of CO2, two modes under general waterlogging had no significant difference; two patterns under Serious waterlogging had significant difference; two modes under general water disaster had significant differences. In terms of CO2emission flux, general water disaster:traditional "oil-rice">"rape-watermelon and corn"; General waterlogging:traditional "oil-rice">"rice shrimp mixed cropping" Serious waterlogging:traditional "oil-rice">"rape-job’s tears". The same trend with CH44) In terms of ecological niche, under general water disaster processing, cole-watermelon and corn pattern compared with conventional planting patterns had more50%time niche, it can use farmland efficiency. In terms of spatial niche, vertical dimension stretched for250cm, it can use energy effectively and improve the organic matter cumulant.Rice shrimp mixed cropping pattern under the general waterlogging processing, in terms of spatial niche, on the basis of the conventional rice planting vertical space extension80cm. utilization of water resources more effective and improve the output; In terms of nutritional niche, reduce pesticide application four times, fertilizer application content1/2. but rice and lobster still normal growth together.