A Study On The Effect Of Sod Culture In Pear Orchards In Southern China

Sod culture in pear orchard is an advanced soil management system, which could improve soil fertility, protect the micro environment of orchard, and contribute the good quality and production of pear fruit. However, this method has not been widely used in southern China. In order to establish a standarized grass planting system, four pear orchards in southern China were chosen to perform sod culture experiment, including orchards in Fuyang of Zhejiang province, Jintang of Sichuan province, Jianning of Fujian province, Anning of Yunnan province. Different herbages including alfalfa (Medicago sativa L.), white clover (Trrifolium repens L.), red clover (Trrifolium pratense L.), rye (Secale cereal L.), tall fescue (Festuca arundinacea Schreb.) and zorro fescue (Vulpia mvuros L.) were planted between the rows, with cleaning tillage servering as the control. Changes of soil physical and chemical properties, soil nutreints, grass growing characteristics, grass nutreints, and fruit qualities were studied to make foundation to the promote use of grassing methods in southern China. The main results are as follows:1. The soil in all of the orchards were acidic, with pH value of deep layer were higher than that of the shallow layer. In general, sod culture decreased pH value of soil; In Fuyang, Jintang, Fuzhou and Kunming, white clover, alfalfa, alfalfa and rye act most effectively in decreasing-pH value of soil, respectively.2. Sod culture in pear orchards increased organic matter contents of soil. What’s more, contents of organic matter in soil increased with the increase of planting years, but showed a reduction tendency with soil depths. For increasing contents of organic matter, the most effective herbage in Fuyang, Jintang, Fuzhou and Kunming was red clover, alfalfa, white clover and alfalfa, respectively. Content of organic matter of soil that covered with grass was significantly higher than that growing with grass, indicate grass covering is more effective in improving soil fertility.3. In general, contents of total N, available N, P and K were increased in grassing land, different herbages had different role in influencing content of soil nutreints. White clover and alflfa act strongly in improving soil nutreints in Fuyang and Jintang, while in Fuzhou and Kunming, only alfalfa increased content of soil nutreints.4. Sod culture had little effect on fruit weight, fruit firmness, total solube solids and total sugar. However, content of total acid were decreased in fruit from grass planting area. In Fuyang, Jintang and Fuzhou, fruit in rye, red clover and rye planting area have the lowest level of total acid, respectively.5. All of the herbages displayed different growth adaptability in different regions. From aspect of grass biological production, rye is good for Fuyang, Jintang and Fuzhou, while alfalfa is good for Kunming, which can be used in improving soil nutreints.