Study On Key Technology Of High Yield And Quality Cultivation Of Green Asparagus

Using Apollo and Grande and Atlas three asparagus species from American as experimental material,the production capacity of different asparagus species,the effect of different amount of nitrogen fertilizer and phosphorus on yield and nutrient quality of green asparagus,the influences of cleaning-stubble method and moulding thickness on the shape and yield of green asparagus were studied from 2006 to 2008 in experimental farm of Inner Mongolia University for Nationalities.The results are as the following:In three experimental species,the number of qualified asparagus,average output rate per day,stem number per plant,weight of per plant and plant diameter of Grande were all highest in 07 and 08 years;the number of first grade asparagus increased with the year increasing;the ratio of unqualified asparagus of three species were 15%more or less;the content of crude protein of Grande was the highest,but lowest for the content of crude fiber;the content of soluble sugar,protein,Vc,rutin and most of mineral elements of Grande species were all highest,but for the content of free aminoacid was lowest,the content of Nitrates was in the middle.The peroxidase of Grande was much bright.In general,the yield and quality of grande were much better than others.The yield of green asparagus and rate of qualified green asparagus goes up with the increase of the amount of nitrogen fertilizer during the harvesting time when the amount of nitrogen fertilizer is within N 0～360 kg/ha.The occurance number of tender stem and the increase of the amount of chlorophyll are the major reason for the increase of the yield of green asparagus,while applying nitrogen fertilizer can make thin asparagus(whose diameter is less than 0.5 cm) long and wide thus decreases the rate of unqualified asparagus.With the increase of amount of nitrogen fertilizer,the content of chlorophyll a and b increase,and the content of carotenoid have no obvious change.The content of crude protein,soluble protein and soluble sugar all increase with the increase of amount of nitrogen fertilizer.The content of mineral elements are much higher when the amount of nitrogen fertilizer is appropriate,but which is lower when the amount of nitrogen is too much or little.Before harvesting time,the content of rutin are much higher and decreases with the increase of amount of nitrogen fertilizer,while after harvesting time,the content of rutin decreases and the difference among each treatment was not obvious.Under this experimental condition,when the amount of nitrogen fertilizer is about N 240 kg/ha,green asparagus not only,has higher yield and better nutrient quality,but also its yield has obvious lifted with the increasing of the nitrogen fertilizer.The yield of green asparagus goes up first and then decreased with the increase of the amount of phosphorus fertilizer during the harvesting time when the amount of phosphorus fertilizer is within P 0～90 kg/ha.The weight of per branches and the increase of the amount of chlorophyll are the major reason for the increase of the yield of green asparagus. With the increase of amount of phosphorus fertilizer,the content of chlorophyll a and b increase,and the content of carotenoid have no obvious change.The content of soluble sugar of P4 was the highest,the content of crude protein,soluble protein all increase with the increase of amount of phosphorus fertilizer.The content of mineral elements are much higher when the amount of phosphorus fertilizer is appropriate,but which is lower when the amount of phosphorus is too much or little.Under this experimental condition,when the amount of phosphorus fertilizer is about N 72 kg/ha,green asparagus not only has higher yield and better nutrient quality.The yield of qualified green asparagus done with digging stubble increased by 9.6%, while the yield of unqualified green asparagus also increased by 5.8%.the reason for digging stubble to improve the yield of green asparagus was that the digging stubble promoted the occurrence of tender stems.The suitable moulding thickness had obvious yield increasing effect,the reason for the yield increasing was that the moulding thickness made the asparagus stem wide and had the weight of per branch improve.With the increasing of moulding thickness,the ratio of bulk-scalp and bent asparagus increased,the first harvesting day delayed,the day yield of green asparagus was high.Suitable moulding thickness could improve the earth temperature and the different moulding treatments were higher than CK.The suitable moulding thickness in the West Liao He Plain of the Inner Mongolia was 5～10cm.