| We investigated the distribution characters of peach tree roots planting in plain clay ridge,mountain regosol and sandy land by improved trenching method. And a farm experiment was carried out to find out the effects of bag-controlled fertilizer, chemical fertilizer ,organic fertilizer and their conjugating on root and upground proportion. The main results showed as follows:1. In terms of planted in plain clay ridge,peach tree root density in ridge was larger than that out of ridge. To 5 years old peach tree, 85.5% of total roots distributed in 20-40 cm soil layer below ground; roots whose diameter <2 mm had the largest distribution extent and density. Whenas roots whose diameter >10 mm was shallow in clay soil, distribution extent was small, and most of those roots distributed in ridge; There was a fake taproot with 2-5mm diameter vertically stretching into ground deep to 70 cm; On the horizontal direction the root distribution extended to moer than 1.7 m range when the soil ridge was 2.0m.2. Growing in sandy land, the root density of peach tree was comparatively small,but had covered large soil volume. To 10 years old peach tree. Most roots were in 60-70cm soil layer below ground, and there were at least one sideroot that spread sheeply to 1.0 m, and some even reached to 1.5m; While 50 cm below ground root distributed comparatively even; Root evenly could reach to 2.5 far away the trunk. Near 0.9 m from the trunk there were the most roots with <2 mm diameter.3. As for peach tree planting in mountain regosol, root density was larger than in plain clay and sandy soil, especially those roots with>10 mm diameter; Growing in mountain regosol, peach tree tended to developing many mesh roots;To 13 years old peach tree, there were few roots in 50 cm soil below ground, by reason of hard solum holding back toproot stretching deeply, which led to some roots gradually perishing. The density of roots with diameter<2 mm was largest in 10-30 cm soil in virtical direction and 1.0 m away in horizental direction. Root in horizental direction could expand to 1.5 m far away from trunk. Yet there were few backbone roots in the virtical direction of terrace. 4. Examination on 2 years old peach trees showed that organic manure treatment had the strongst growth. Compared with the CK, organic manure increased the number of the first lateral roots by 54.76%, expanded extended radius by 20.85%, raised the root angle span, increased total root dry weight by 1.48 times, <2 mm lateral roots by 1.21 times and> 5 mm lateral roots by 3.83 times. Bag-controlled fertilizer treatment was second only to organic treatment. Compared with chemical fertilizer treatment, bag-controlled fertilizer had increased the number of the first lateral roots by 20.9%, increased total dry weight of root significantly and promoted shoot growth much obviously. Chemical fertilizer + organic fertilizer treatment had inhibited the growth of young tree.To chemical fertilizer + organic fertilizer treatment, root biomass and shoot growth were lower than the CK, the first lateral roots were lower than CK by 38.09%, the minimum root angle was significantly decreased and root angle span was increased, and for that root were shallower. The inhibition of bag-controlled fertilizer + organic fertilizer to young peach trees was not so serious as chemical fertilizer + organic fertilizer.5. Examination on 10 years old peach trees showed that fertilization could advance roots hyperplasia. Organic fertilizer had the worst roots hyperplasia effection,could not advance the yield evidently,but it had improved the quality. Bag-controlled fertilizer could greatly advanced the <2 mm hyperplasia, improved the fruit-setting and the yild. But chemical fertilizer treatment and bag-controlled fertilizer + organic fertilizer treatment were not so well as bag-controlled fertilizer treatment. Although chemical fertilizer+ organic fertilizer treatment largely advance root hyperplasia, it reduced rate of fruit-setting and had not improve yield dramaticly.
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