| Shanlan upland rice is one of the upland rice in mountainous area created by Li&Miao minority people in the long-term practice in Hainan province.Traditional slash-and-burn cultivation mode of Shanlan upland rice is not only single but also detrimental to the environment.In recent years because of the prohibition from burning the mountains and deforestation,the problems of low yield and benefit have led to reduce planting area of Shanlan upland rice.In order to further development of Shanlan upland rice,carry traditional national industry forward and abandon the slash-and-burn patterns because of destroying ecological environment,it is necessary to explore new pattern of cultivation of the Shanlan upland rice.The farming of Shanlan upland rice was under upland conditions and planting location had limitations in past.This paper tries to change the traditional pattern,expand planting areas of Shanlan upland rice according to the make use of paddy cultivation of upland rice and discuss the paddy cultivation techniques of Shanlan upland rice for high yield.Therefore,morphological,physiological characteristics and yield of Shanlan upland rice under paddy cultivation had been studied in field experiment in order to find the paddy cultivation techniques of Shanlan upland rice for high yield.Moreover,the effects of the rice-blast control under diversified cropping of Shanlan upland rice were studied.First of all,some aspects of Shanlan upland rice were respectively compared about drought-resistant physiology indexes,yield,agronomic characters,the influence of water conservation and effects on weed control under three cultivation modes:paddy,rice straw mulching and upland cultivation,and further to analyze whether paddy and rice straw mulching to be used in Shaman upland rice.Secondly,paddy cultivation of Shaman upland rice was applied to Shaman upland rice-rice intercropping in order to make a research about the influence of control of rice blast by diversified cropping.Setting different gradients of row ratio in Shaman upland rice-hybrid rice intercropping,comparison was made about the incidence and disease index of rice blast under different collocations to make the best scheme of Shaman upland rice-hybrid rice intercropping collocation.The research results are as following.(1)Paddy and rice straw mulching alleviated drought stress on Shaman upland rice and the effect of former cultivation was stronger,reduced contents of MDA and soluble protein inhibited the activity of POD and degradation of Chlorophyll content of sword leaf.(2)Compared with upland cultivation,available tillers respectively increased 141.03%and 52.33%under paddy and rice straw mulching;the yield increased by 267.44%and 91.04%respectively;plant height increased by 16.69%and 30.62%respectively;length of sword leaf increased by 6.62%and 6.62%respectively.There was significant difference on panicle number per hill,grain number and fruiting rate among different cultivation patterns,the order of which was as follows:paddy>rice straw mulching>upland.There were significant differences about thousand seed weight under paddy cultivation compared to rice straw mulching and upland cultivation.Whereas there were no significant differences about ear length among cultivation patterns.(3)There were great influence on the water content of surface soil(0?10 cm)under different cultivation modes.The moisture content of soil layers in paddy and rice straw mulching were significantly higher than upland cultivation;rice straw mulching had strong water-saving effect,with water used efficiency(WUE)of 1.45 kg·m-3.The results suggested that water use efficiency in rice straw mulch was 1.3 times more than that of rice cultivated under paddy cultivation.Water use efficiency of Shaman upland rice was only 0.3 kg·m-3 under paddy cultivation,reduced by 52.38%compared with the traditional upland cultivation.Compared with upland cultivation,the growth period of Shaman upland rice was respectively shortened 12 days and 5 days under paddy and rice straw mulching cultivation.(4)Compared to upland cultivation,weed-control effect was significant with weeds covering degree respectively decreasing by 59.53%and 42.33%under paddy and rice straw mulching mode;there were obvious changes of weed species and its ratio in different modes:the population of Broad-leaved cotyledons weeds increased,narrow-leaved dicotyledonous and gramineous weeds declined under paddy condition.(5)Shanlan upland rice-hybrid rice intercropping had effective control on the rice blast and increased the yield of rice.There were significantly different about incidence,disease index and yield of hybrid rice among different line-number collocation "2+X" of Shanlan upland rice-hybrid rice intercropping.The results suggested that as row number of hybrid rice "X" gets bigger,effect of rice-blast control lower.Incidence and disease index of rice blast of "2+2" line-number collocation of Shanlan upland rice-hybrid rice intercropping was 14.5%and 3.83%respectively and control efficiency increased by 68.53%,the effect of rice-blast control was best among another treatments.The results also demonstrated that there were significant differences in yield of hybrid rice among different line-number collocation.In the line-number collocation of Shanlan upland rice-hybrid rice intercropping,as "X" got bigger,the yield of hybrid rice first rose up and then moved down,"2+6" and "2+8" Shanlan upland rice-hybrid rice intercropping mode not only improved the effect of rice-blast control but also increased yield of hybrid rice. |
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