Yield Of Different Oil Rice Multiple Cropping Models In Northern Hunan Research On The Utilization Of Solar Thermal And Nutrient Resources

The oil rice rotation model is one of the main crop production models in Hunan Province,and its planting area accounts for 45% of the total rice field planting area in the province.North Hunan is located in the transition zone from subtropical climate to monsoon humid climate.It is the main planting area of oil rice rotation in Hunan Province.one.In this study,the annual yield and low resource utilization efficiency caused by the unreasonable allocation of solar and thermal resources and the mismatch of nutrient resources and crop growth requirements during the multiple cropping seasons in the northern Hunan region were investigated.Research on the impact of nutrient resource utilization,with a view to providing theoretical and technical support for the rational selection of the rotation mode of solar thermal and efficient use of nutrient resources in the region.In 2018-2019,in Nan County,Xiangbei region,through the Datian community experiment,oil-rice(high-quality conventional rice,T1),oil-rice(super hybrid rice,T2),winter leisure-rice(super hybrid rice,T3),Oil-rice-rice(T4),winter leisure-rice-rice(T5)five planting modes of crop growth,light and heat resource utilization,nutrient resource utilization and other indicators were compared and analyzed.The results showed that:1.The annual output of the T4 model is the highest,reaching 13463.4kg / hm2,followed by the T5 model;the annual output of the T4 model is significantly higher than the T1,T2,and T3 models,and there is no significant difference from the T5 model;the rapeseed production is the highest in the T2 model,reaching 1857.6kg / hm2,significantly higher than T1 and T4 models,respectively increased by 9.3%,13.6%;in the one-season rice yield,T2 and T3 models were significantly higher than T1 model,respectively increased by15.6%,20.2%;double-season rice yield,T5 model Significantly higher than T4 mode.The T4 model showed a higher annual dry matter quality.The dry matter accumulation of single-season rice was the highest in the T1 model,which was 6.0%,9.2%,11.1%,and18.4% higher than T2,T3,T5 late rice,and T4 late rice,respectively;The annual dry matter accumulation of the T1 and T2 models is higher than that of the T4 and T5 double-season late rice.Compared with the oil-rice-oil-rice-rice and winter leisure-rice-rice models,the oil-rice rotation model is more favorable for rice growth.Accumulation of dry matter during the period.2.The annual effective accumulated temperature performance of each mode is T4> T2>T1> T5> T3,the annual effective accumulated temperature utilization rate is consistent with the annual effective accumulated temperature performance,and the annual effective accumulated temperature utilization rate of T2 mode reaches more than 90%.The annual heat energy utilization efficiency is represented by T5> T4> T2> T3> T1.The heat utilization efficiency of T5 mode is significantly higher than other modes,which is 12.7%-51.8% higher than other modes.T2 mode is 3.6% higher than T3 and T1 modes.11.1%.3.Comparison of soil nutrients among the models,the T2 model p H value,alkaline nitrogen and total nitrogen content are higher than the T3 model,the total nitrogen content increased by 3.8%,the available phosphorus,available potassium and organic matter content were not significantly different.In contrast,the soil nutrients of the T2 model are superior to other models.Compared with the accumulation of plant nutrients,the nitrogen content of grains in the T1 model during maturity increased by 12.6% and 17.9% compared to the T2 and T3 models,respectively,and the T4 late rice increased by 11.1% compared to the T5 late rice;the phosphorus and potassium in the grains of the T1,T2 and T3 models during mature period There was no significant difference in the element content.The phosphorus content of T4 early rice during the mature period was significantly higher than that of T5 early rice,an increase of 20%.The difference between the potassium content in the mature period of T4 and T5 models was not significant;the total nitrogen accumulation and nitrogen absorption of T1 and T2 models The rates were significantly higher than the T3 mode,the total nitrogen accumulation increased by 49.4% and 16.1%,respectively,and the nitrogen absorption rate increased by 50.0% and 16.1%;the total phosphorus accumulation and phosphorus absorption rate in the T1 mode were significantly higher than the T3 mode,Increased by24.7% and 24.8% respectively,the difference in total potassium accumulation and potassium absorption rate was not significant.This shows that planting rape in winter significantly increases the nitrogen and phosphorus content of rice.Based on the above evaluation indicators,compared with T4 model,T2 model(oil-rice model)has lower annual yield and utilization efficiency of solar and thermal resources,but it increases soil nutrient content,which is beneficial to cultivated land,improves cultivated land quality and rice field sustainability Production;Compared with T1 model and T3 model,the annual output,utilization efficiency of solar thermal resources and soil nutrient content of T2 model have been improved,so that the solar thermal resources in the region can be fully utilized without seasonal contradictions in the annual cropping.,And can achieve sustainable high-yield rice through cultivation,so the T2 model is a relatively suitable planting model in the region.