Study On Key Technologies For High Efficiency Production Of Alfalfa In Central Inner Mongolia

The central part of Inner Mongolia is the main production area of alfalfa in the province.and the level of yield and quality of alfalfa in the area have been below the national average level,the technique for high efficiency production of alfalfa has lagged behind the current development of alfalfa industry,with the rapid development of alfalfa industry in recent years.The key technique such as suitable variety selection,seeding density,fertilization ratio,and coupling of water and fertilizer management were studied in the study.Three representative areas in central Inner Mongolia were selected for multi-year experiments.The experimental design included single-factor randomized block design,soil testing and fertilization test design,and quadratic regression saturated D416 optimal test design.The growth characteristilcs,forage yield,nutrient quality and soil nutrients were measured and analyzed,and the following results were obtained:1.The growth characteristics,forage yield and nutrient quality of different alfalfa varieties were significantly different on the comprehensive evaluation of alfalfa varieties,the plant height and growth rate were highest for variety Zhongmu No.1,the SLR was lowest for variety Zhongcao No.3,the FDR was highest for variety WL319HQ,the forage yield was highest for variety Caoyuan No.3,and the variety Zhongcao No.3 performed better on CP,ADF,DDF and RFV among all of the tested varieties.It could be concluded that the varieties such as Zhongmu No.l,Caoyuan No.3 and Zhongcao No.3 have better comprehensive performance and that they are suitable for popularization and application in central Inner Mongolia according to the gray correlation evaluation.2.There existed no significant effect on the plant height and growth rate within 30-60 cm row spacing,but the variation of row spacing with the growth period existed a significant effect on plant height and growth rate within the 10-30cm for screening experiment of planting density.The SLR was influenced significantly by row spacing within the 10-60cm row spacing,it decreased first and then increased with the increase of the row spacing.The forage yield of alfalfa was also influenced significantly by row spacing,and it decreased with the increase of row spacing.The CP and RFV of alfalfa were significantly different under the row spacing,they increased first and then decreased with the increase of row spacing within 10-30cm row spacing,and they decreased with the increase of row spacing within 30-60cm.The ADF and NDF were also influenced significantly by row spacing,they increased first and then decreased with the increase of row spacing within 10-30cm,and they increased with the increase of row spacing within 30-60cm.The forage yield and quality of alfalfa are better within 10-30cm row spacing,which are suitable for promotion and application in central Inner Mongolia.3.The plant height and growth rate,CP and RFV could be increased significantly,but the SLR,NDF and ADF could be reduced by the fertilization,otherwise the fertilization could increase soil organic matter and reduce soil pH.The contents of total nitrogen,alkali nitrogen,total phosphorus,available phosphorus,total potassium and available potassium in the soil could be increased by the fertilization.Fertilization can significantly increase the yield of alfalfa.The effects of nitrogen,phosphorus and potassium on forage yield varied with experimental conditions.The contribution of fertilizers to forage yield was K>N>P at the early growth stage,the forage yield was effected negatively by the interaction of nitrogen-potassiurn,and it was effected positively by the interaction of nitrogen-phosphorus mnd phosphorus-potassium in the case of potassium deficiency.The effect of fertilizer on forage yield was N>P>K at the early growth stage,the forage yield was effected negatively by the interaction of nitrogen-phosphorus,and it was effected positively by the interaction of nitrogen-potassium and phosphorus-potassium in the area of phosphorus deficiency.It was concluded that the recommended fertilization ratio is 25.08?30.69kg/hm2 for phosphate fertilizer,54.38?69.60kg/hm2 for potassium fertilizer,and 58.50?77.63kg/hm2 for nitrogen fertilizer in the potassium deficient area,The recommended fertilization ratio is 147.68?185.63kg/hm2 for phosphate fertilizer,51.38?66.75kg/hm2 for potassium fertilizer,and 40.80?53.10kg/hm2 for nitrogen fertilizer in the phosphorus deficient area..4.The plant height,growth rate,CP and RFV of alfalfa could be increased significantly by the coupling effect of water and fertilizer,and the SLR,ADF and NDF could be reduced by the effect of water and fertilizer.The coupling of water and fertilizer had significant effects on the nutritional quality of alfalfa,the effect of water was more efficient than that of fertilizer.Water and fertilizer coupling significantly increased the forage yield of alfalfa,the effect of water and fertilizer on yield was water>nitrogen>phosphorus>potassium.The interaction between water and fertilizer factors was signifieant.The optimal ratio of water to fertilizer is 90kg/hm2 for nitrogen fertilizer,75kg/hm2 for phosphate fertilizer,45kg/hm2 for potassium fertilizer,and 400 mm for imgation in central Inner Mongolia.