| In order to discuss the proper preceding crops in North Areas of Yinshan Mountain in Inner Mongolia,’Kexin1’as experiments materials, the field random block design was adopted to study growth, soil properties and disease of potato in nine preceding crops treatments, which included fallow, bea green manure, naked oats, canola, buckwheat, sunflower, flax, potatoes for3years and4years continuous cropping. The main conclusion were as follows:1With the advance of potato growing period, plant height and stem under different preceding treatments were gradually increasing, except buckwheat, average of plant height in other preceding treatments were significantly higher than in the treatments of potatoes for3years and4years continuous cropping during potato growing period, sunflower stubble was the highest, it was52.25cm, the second were bea green manure, naked oats, fallow stubble, they were significantly higher than flax, canola, buckwheat stubble. Average of plant stems in other preceding treatments were significantly higher than in the treatments of potatoes for3years and4years continuous cropping during potato growing period, sunflower stubble was the highest, it was1.39cm, it showed significant differences with other preceding treatments except with bea green manure and fallow stubble, the second was bea green manure stubble, it also showed significant differences with other preceding treatments. The dry matter accumulation of potato stems and leaves increased and then reduced, the dry matter accumulation of potato leaves and stems were high in the treatment of bea green manure stubble, it was significantly higher than potatoes for3years and4years continuous cropping; the dry matter accumulation of potato tuber showed a rising trend, average of the dry matter accumulation of potato tuber in other preceding treatment was significantly higher than in the treatments of potatoes for3years and4years continuous cropping during potato growing period, bea green manure and fallow stubble were highest, the second were naked oats and canola stubble; the dry matter accumulation of whole plant showed a rising trend, average of the dry matter accumulation of whole plant was highest in the treatment of bea green manure stubble, the second was fallow stubble, they were significantly higher than sunflower, flax, buckwheat, potatoes for3years and4years continuous cropping. All treatments had no significant effect on the distribution rate of the dry matter in the stems and leaves, the distribution rate of the dry matter in tubers was higher in the treatments of fallow, naked oats, canola, bea green manure stubble, they were significantly higher than the sunflower stubble.2In the whole period, leaf SPAD of all treatments were gradually decreased, leaf SPAD of bea green manure stubble was significantly highest, the second were oat and fallow stubble, they were significantly higher than potatoes for3years and4years continuous cropping. LAI increased and then reduced, reaching the peak after emergence65d, in the whole growth period, bea green manure stubble was highest, the second were fallow、naked oats and canola stubble, they were significantly higher than buckwheat flax and potatoes for3years and4years continuous cropping, the contents of Pn、Gs、Ci and Tr of potato leaves were the largest in the treatment of bea green manure stubble, the second were fallow and naked oats stubble.3Before the potato emergence, diurnal average variation of soil temperature was highest in the treatment of sunflower stubble, it was22.7℃, followed by naked oats and potatoes for3years continuous cropping, it were22.6℃and22.5℃, they were significantly higher than flax stubble0.8℃,0.7℃,0.6℃.4With the advance of potato growing period, the content of soil organic> nitrogen and K in different preceding crops treatments showed a trend of gradual decline in the0-20cm and0-40cm soil layer, soil available phosphorus had a slightly increase at75d after potato emergence. Bea green manure and canola stubble could significantly improve the content of soil organic, the content of soil nitrogen was high in the treatments of bea green manure and fallow stubble, the soil available phosphorus show inconsistent rule in all treatments, fallow, pea green manure and oat stubble could significantly improve content of soil K.5With the advance of potato growing period, soil enzyme activity in treatments of preceding crops in the soil layer all showed rule of low-high-low, soil enzyme activity was reducing with the deepening of the soil, bea green manure、fallow and canola stubble could significantly improve soil oil catalase activity and urease activity, soil invertase activity was higher in the treatments of pea green manure, fallow and naked oats stubble, potatoes for3years and4years continuous cropping of soil enzyme activity were lowest than other preceding crops treatments. In conclusion, pea green manure、fallow、canola and naked oats stubble had rich soil fertility levels and stronger soil enzyme activity, it showed that they helped to improve soil fertility compareing with other preceding crops treatments. 6Potato yield under different preceding treatment were increased significantly, yields of pea green manure stubble was extremely significantly higher than other treatments, it was50168.0kg/hm2, potato for4years continuous cropping yield was the lowest. The preceding crops treatment significantly improved the potato tuber nutrition ingredient, the content of starch was the highest in the treatment of naked oats stubble (46.26%), the content of protein was the highest in the treatment of pea green manure stubble (8.13%), the content of reducing sugar was the highest in the treatment of4years continuous cropping; other treatments increased the content of vitamin C, but the difference was not obvious.7The rate and index of potato black scurf were lowest in the treatment of pea green manure stubble, the second was buckwheat stubble; the rate of potato fusarium wilt was the lightest in the treatment of pea green manure stubble. |
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