| The intercropping of Gramineae and Leguminosae is the most widely used and successful combination in traditional intercropping.The two promote each other’s growth,improve resource utilization,and reduce the dependence of crops on chemical fertilizers.Relevant research shows that the intercropping system has obvious advantages in increasing production.The purpose of this study was to explore the effects of different nitrogen application rates and row ratios on the yield,quality and physiological characteristics of japonica hybrid rice in upland cultivation.The two-factor split-plot experiment was carried out with Dian-type japonica hybrid rice variety’Dianheyou 615’and soybean variety’Yunhuang 13’as test materials.The main area was different nitrogen application levels A1(5kg/mu),A2(10 kg/mu),A3(15 kg/mu),and the sub-area was rice/soybean intercropping different row ratios B1(4:4),B2(4:2),B3(4:1),rice and soybean monocultures were set up in the protection row;the effects of japonica hybrid rice/soybean intercropping on crop growth and development,light resource utilization,yield and quality were analyzed and evaluated,and the best combination mode of rice and soybean intercropping under different treatments was screened.The main results are as follows:(1)Japonica hybrid rice and soybean intercropping upland cultivation in high altitude area test demonstration overall growth is good,normal growth and development of rice and beans.The order of comprehensive yield of rice and bean in 9 treatments was A2B3>A3B2>A1B2>A1B3>A2B2>A2B1>A3B3>A1B1>CK>A3B1.The total yield of rice and beans in the best yield model A2B3 was 622.7 kg/mu,of which rice yield was 506.88 kg/mu and soybean yield was 115.83 kg/mu.From the perspective of comprehensive yields of rice and bean,A3B2 and A1B2 are also good intercropping modes,and their comprehensive yields of rice and bean are 565.98 kg/mu and 554.96 kg/mu,respectively.(2)With the increase of nitrogen application rate,the protein content of rice has been increased,amylose and taste value has been decreased,but the overall amplitude is not large.The protein content of A3B3 was the highest 7.33%,the amylose content of A1B2 was the highest 15.33%,the taste value of A1B3 was the highest 79.With the decrease of row number,protein content,amylose content and taste value decreased first and then increased,the order of the first two was B1>B3>B2,and the latter was B3>B1>B2.(3)With the increase of nitrogen application rate,the plant height and seed setting of rice increased first and then decreased,and the order was A2>A3>A1.The plant height of A2B3 was the highest(109.51 cm).The panicle length of rice decreased first and then increased,and the panicle weight decreased.The plant height and bottom pod height of soybean decreased first and then increased,and the number of main stem nodes and branches increased.With the decrease of the number of intercropping soybean rows,the pollen fertility and seed setting rate of rice increased,which was the biological premise of stable yield and income increase.The highest pollen fertility of A1B2 was 87.50%,and the highest seed setting rate of A2B3 was 91.23%.(4)With the increase of nitrogen application rate,the flag leaf length and width of rice decreased first and then increased,and the relative chlorophyll content and leaf area increased first and then decreased.The maximum relative chlorophyll content of A2B3 was40.15,and the maximum leaf area of A3B2 was 49.87 cm~2.The interaction of different nitrogen application rates,different row ratios,different nitrogen application rates and row ratios had significant effects on the relative chlorophyll content of soybean,and the three had little effect on the leaf length and leaf area of soybean.With the decrease of the number of intercropping soybean rows,the leaf width of soybean increased continuously,and the relative content of chlorophyll decreased continuously.The leaf width of A1B2 was 7.52 cm,and the relative content of chlorophyll of A2B1 was 48.35.(5)Different nitrogen application rates and row ratios had great effects on root length and root weight of rice,root length,nodule number and nodule dry weight of soybean,but had little effect on root shoot ratio of rice and root dry weight of soybean.On the whole,the maximum root length of A2B2 in rice was 14.23 cm,and the maximum root length of A3B2in bean was 37.23 cm.The number of CK nodules in soybean was 20.33,and the order was CK>A1B1>A3B3>A1B2>A1B3>A2B2>A2B3>A3B2>A2B1>A3B1.(6)The effects of different nitrogen application rates and row ratios of rice/soybean intercropping on the relative expression of nitrogen efficient utilization gene NRT1.1B in japonica hybrid rice were extremely significant.With the increase of nitrogen application rate,the relative expression decreased,and with the increase of intercropping soybean rows,the relative expression increased.The relative expression of all treatments in the experiment was up-regulated compared with CK.The relative expression of A1B1 treatment was the largest,which was 15.44 times higher than CK,and the relative expression of A3B3treatment was the smallest,which was 2.26 times higher than CK.This study preliminarily constructed a set of Dian-type japonica hybrid rice/soybean intercropping,and provided a theoretical basis for the analysis of biological,agronomic,agricultural ecology and economic effects of japonica hybrid rice/soybean intercropping. |
PDF Full Text Request