Studies On Soil Adaptability And Ecological Layout Of Grape In The Dry River Valleys Of The Upper Reaches Of Minjiang River

The upper reaches of Minjiang River are an important part of ecological and environments construction in the upper reaches of the Yangtzi River. With abundant sunlight and heat, there ai resourceful advantages to develop characteristic agriculture given priority to grape and other temperat defoliated fruit trees in the dry river valley. By studying climatic and soil conditions suitable for grap growing and selection of fine varieties of grapes, the author put forward a reasonable ecological layout i order to provide scientific basis for the development of viticulture and agricultural structure adjustment i the dry river valleys of the upper reaches of Mijiang River. The results were clarified as follows.1. There are excellent climatic and soil conditions for viticulture development in the dry river valley of the upper reaches of Mijiang River, where varieties of both fresh and brewing grapes showed goo-biological characteristics and reached high yield of quality fruits. Therefore the investigating areas ar ecological adaptive zone of grapes.2. Most soils are of cinnamon and neo-aoouviao, which are rich in calcium carbonate (CaCO3) and ar alkalescence with pH of 7.5-8.5. Soil depth varied dramatically from 30cm to 100cm. Texture of soils i dominated by gravel soil (light and mid soil) with well drainage and ventilation. However, part of the soil over consists of gravels (30~70%), which makes the soil inferior in fertility conservation. To construe grapery, the suitable land should be selected that has relatively deep roam soils with good texture ii terraces and has sufficient irrigation as well.3. The soils are mostly short of Organic matters and nitrogen (N), but they have sufficient phosphoru (P) and potassium (K). Owing to the high content of calcareousness, the soils can provide relatively lov source of trace nutrition of Zn, Mn and Fe. Analysis results of foliage samples of grapes coincide with th< soil nutrition conditions. Through the diagnosis of soil nutrition, application of fertilizers can balance thi nutrients.4. The adaptable soil conditions of grape growing are the gravel, sandy and clay roam soil with goo< texture, 80~ 100cm in depth, below 1.5~2.0m in groundwater level, neutral to slightly alkaline with pF 7.5~8.5, under 50% of rock contents and well irrigated. It is better to choose relatively flat land and soil: that are affluent in nutrients.5. Based on the local climate and landform characteristics associating with soil conditions required for grape growing, three ranks of adaptable zoning were suggested in the dry river valleys of the upper reaches of Minjiang River. The optimum zone or rank I adaptability mainly locates in the areas 30~100m higher than the river course with altitudes between 1400~1900m in valley of Minjian River and its tributaries of Zagunao River and Heishui River. The adaptable zone or rank II adaptability distributes in the optimum zone but 100~150m higher than the river course and in the areas 30~100m higher than the river course of the regions downward from Weizhou town, Wenchuan county as well as in the sub-tributaries of Heishui River and Zagunao River. The less adaptable zone or rank III adaptability mostly situates in the areas upward the optimum zone with relatively higher altitudes, lower heat quantities, more precipitation and steeper slopes.