Study On Key Cultivation Technology Of Cyperus Esculentus L. In Black Soil Area Of Jilin Province

Cyperus esculentus L.is a new crop integrating oil,grain,animal husbandry and feeding.The cultivation area of Cyperus esculentus L.is increasing year by year in China.In this paper,the effects of different planting densities and combined application of NITROGEN,phosphorus and potassium on yield and its constituent factors,agronomic characters and physiological characteristics of Cyperus esculentus L.were studied,and the optimal planting density and fertilization ratio of Cyperus esculentus L.in black soil area of Jilin Province under the current experimental conditions were discussed,aiming to provide theoretical basis and technical support for high-yield and high-efficient cultivation of Cyperus esculentus L.The main results are as follows:1.Among the three planting densities M1（19.23×104 hole/ha）,M2（12.82×104hole/ha）and M3（10.26×104 hole/ha）,the tuber yield was the highest under M1 density,which was 3085.96 kg/ha,7.73%-33.99%higher than other treatments.However,there was no significant difference between M1 and M3 treatments,and there was no significant correlation between planting density and yield.With the increase of planting density,100-grain weight of tuber tended to decrease and plant height tended to increase.In terms of yield composition,tuber yield was positively correlated with aboveground yield,tiller number per unit area,tuber number per unit area,and negatively correlated with 100-grain weight,but had no correlation with photosynthetic rate and other physiological indexes.2.Nitrogen,phosphorus and potassium fertilizer and its rational combination could promote the growth of Cyperus esculentus L.,significantly promote the plant height,tiller number per unit area and photosynthetic rate,and then significantly increase the tuber yield of Cyperus esculentus L.According to the unary quadratic equation fitting,the fitting equations for N,P₂O₅,K₂O and tuber yield data are as follows:Y=-0.0734x~2+18.69x+3937.5（R~2=0.8375）,Y=-0.0615x~2+18.44x+3175.5（R~2=0.4841）and Y=-0.2605x~2+58.02x+2014.9（R~2=0.9988）,The dosage of N,P₂O₅,K₂O were 119.42 kg/ha,141.80 kg/haand 109.27 kg/ha,respectively,and the optimal yield was 5147.08 kg/ha,4565.46 kg/haand 4148.69 kg/ha,respectively.Under the combined application of NPK fertilizer,the highest yield of N2P2K2 treatment（90kg/haN,135 kg/haP₂O₅,113 kg/haK₂O）was 5321.07kg/ha,which was consistent with the current recommended combined application of NPK fertilizer.