Survey And Investigation On Mulberry Field Soil In Jia Hu Plain Of The Northern Zhejiang Province

Jiahu plain is located at the lower Yangtze River delta. Which enjoys the fameof "town of fish and rice, and home of silk". It now has 55,000 hectare mulberryfields. The formation, classification and characteristics of representativemulberry field soils were investigated. The mulberry soils are classified asAquent order, orthic Asquent suborder, Fluvio aquic soil group, Anthrcumulicfine texture soil genus, and then are divided into 3soil species, such asMoctnnulic Clayey Soil, Anthrocumulic Loamy Soil, and Anthrcumulicsilty soil.The physical, chemical and microbiological properties of different mulberryfield soi1s have been tested in laboratory. On the founation of previous data,there are three problems of mulberry field soils were obtained:1 .In recent years, the acidification of mulberry field soil was very serious. thesoil was strong acidic (pH=5.0 approximately), stick-hardened, and mulberrytree developed slower, fertilizer react slowly, It is also impossible to obtain thehigh yield although fertilizer were used heavy.2. The deficiency of k element nutrient in mulberry tree is very distinct, thesymptom of mulberry leaves are spreaded, available k of mulberry soil decreasesby 14.7%.3. The soil fertilities of renewed mulberry field are declining, total nitrogendecreased by 69.32%, organic matter decreased by 64.41%. But the micro-orghasms (bacteria, fungi and actinomycetes) are no significant distinction.By investigation and analysis, 17 indexes of physical, chemical propertes ofhigh yield mulberry field soils were proposed. Some control policies ofmulberry soil acidification wee pointed out. Such as aPPly lime fertilizer.Organic otr used, balanced fertilization and green manur plared etC. thisprovides a sound basis for conStrUCting high yield mulbeny field soils.