| Dongting lake was important agricultural production base.it also was one of the floods occur most frequently district in China.This paper attempted to analysis on the major agricultural meteorological disasters in Dongting lake,reveal the development laws of agrometeorological disaster.Then the efficient model and key technology were put forward low-lying rice fields.It could provide scientific theory and the practice basis to escaping agricultural disaster in the new period of Dongting lake.The main results were as follows:1.Dongting lake agricultural meteorological disaster classification and its lawsThe main meteorological disasters included floods, drought, low temperature in Dongting lake.The main meteorological disasters on agricultural production named late spring cold,rainy,cold May,floods,summer droughts,August low temperature,high temperature heat harm, cold dew wind, freezing cold, etc. The frequency of floods was26%-60%. Floods occured generally in the Midwest and northeast lake in this district. The frequency of spring rainy was very higher than autumn rainy, which was55%-82%. The frequency of drought was32%～63%. The Most dry lakes areas was YuanJiang, Nanxian, the probability was57%～63%. Low temperature disaster probability was relatively frequent, was above50%(1in2years), exclusive of August low temperature.2.Selection of escapting disaster planting mode in Dongting lakeThe mode of middle-season rice-flax fiber combination (oil) was the most cost-effective pattern in the Low-lying paddy among4planting modes (flax fiber combination (oil)-rice, rape-middle-season rice,no crop in winter-early rice and late rice, barley-cropping (early rice and late rice) four patterns). The output value of middle-season rice was1522.63yuan/mu, which was higher32.59%than no crop in winter-early rice and late rice. and higher38.85%,10.45%compared with rape+middle-season rice and the barley-cropping (early rice and late rice) mode. The mode of middle-season rice-flax fiber combination (oil) might reduce the labor input, which could save2-8human input, about200-800yuan/mu (as local wages100yuan/day) artificial cost savings. Barley-cropping (early rice and late rice) mode increased20.05%output value than the no crop in winter+early rice and late rice.It use of sowing winter agriculture resources. The middle-season rice-flax model can avoid late spring coldness and cold dew wind. Second, compared with rapeseed winter crop flax can avoid the seedling drought, bud stage, which sounds at low temperature, warm winter early moss, and so on.3Key technology to avoid disaster3.1Escaping key technologies of flaxThe pot disaster simulation experiment of flax were done. The result showed flax could avoid even the rain and low temperatures early warm spring sprouts comprided with rape because it have strong resistance to waterlogging in in the early growth stage. During budding and flowering season, the flax was higher sensitive for waterlogging. When the flax was flooding in budding and flowering stage, seed yield of flax were reduced up to80%, but the stem yield cut a lesser exten. In the Dongting Lake area, planting flax direct harvesting of the original stem when it was rainy in later growth stage to achieve stable production results.Among all tested flax species, JinYa10production ranking was first. Stem yield of JinYa10was5285.98kg/hm2, seed production was402.7kg/hm2. The yield of the LunXuan2production ranking was second. Stem yield and seed of LunXuan2were5225.95kg/hm2and375.19kg/hm2in turn yields. The lodging resistance ability of the varieties of JinYa10and LunXuan2,5level of lodging rate was0.Tillage cultivation measures on treatment compared Rotary handle raw stems yield9.45%,0.37%yield seeds, tillage and rotary handle five lodging rates were0," it’s the best way to develop the lodging resistance by early sowing no-till no fertilizing,lighter level(0to4)the sum rate of lodging is18.33%,the highest level(5)the rate of lodging is o,stem yield and seed yield highest,followed in turn8375.77kg/hm2and804.46kg/hm2.Combined2012(April-May rainfall of487.1mm Including five times the heavy rain, heavy rain2times),2013years (April-May rainfall of288.6mm four against the heavy rain) special climatic conditions shows that flax harvest stem yield directly to avoid the rotten field caused by long-term water, compared with growth of canola, flax appreciation of winter crops93.48%.3.2Escaping the key technologies in riceThe escaping technologies of low-lying paddy rice included the following aspects.Frist, selecting suitable varieties. The early rice Tanliangyou83and Zhuliangyou08increased by26.55%and26.55%respectively than control Lingliangyou211; Compared with T180, the late rice Fengyuanyou299and Ⅱ you578increased by9.55%and8.79%respectively.Second, determine the optimum sowing varieties. Early sowing rice varieties moderately plug, so heading and flowering in mid-June, late sowing season rice varieties moderately late interpolation, so heading and flowering in mid-August. The results showed that in2013accounted for by the perennial flower Sowing late May early June to early May15, the highest yield was773.46kg/667m2, respectively, compared with May25, June5accounted for planting flower yield per acre17.91%and28.23%. Double cropping rice in a safe heading period (September15) Late Late sowing broadcast earlier increase of67.90%; Third,scientific irrigation, resist heat damage. Plenty of water, you can take day night row irrigation, lowering the temperature field. Four,For in cold dew wind, measures should be taken to agribusiness, transplanting seedlings transplanting larger increase of51.97%, before the advent of cold dew wind, filling the night deepwater (7-10cm), and so on.Combined with special climatic conditions of4-5month of2012which included sounds, flooding, heavy rains in June.due to avoid the heavy rain in June,fiber combination oil flax-middle-season rice have appreciated by26.85%and21.13%than rape-middle season and double-season DongXian.Combined with2013(July and August drought, September torrential rain, cold dew wind, etc.) of the special climate conditions, because of avoid the cold dew wind disasters at low temperature,fiber and hemp-middle-season rice have appreciated by38.85%and32.59%respectively than rape-middle-season rice and double-season DongXian. |
PDF Full Text Request