Dynamic Characteristic Of Soil Nutrients And Runoff In Different Plant Fence Of 3 Economic Forests

Soil erosion and water loss is still a very serious problem in red soil hilly region of southern China.Serious soil erosion leads ecological destruction and affects people’s production.The soil erosion and water loss in the economic forest in recent years has been pay abundant attention because of the serious economic losses in some areas.In this paper,the runoff pools were established in three economic forests named waxberry forest,chestnut forest and gingko forest in Changting County,Fujian Province.The gardenia resistance control arrangement and paspalum natatumn resistance control arrangement were established under waxberry forest.The daylily resistance control arrangement and the micro-topography reform resistance control arrangement were established under chestnut forest.The Taiwan-daylily resistance control arrangement and myrtle resistance control arrangement were established under gingko forest.Soil samples were collected in March,June,September and December,2016.Analyzed the contents of soil soluble carbon and nitrogen.The runoff pool was constructed at the bottom of the slope to collect runoff and sediment.In order to reveal the rule of runoff and sediment and select the best control mode to decrease soil and water conservation.The main results are as follows:(1)In the study of the waxberry forest,the gardenia and paspalum natatumn resistance control arrangement could increase soil pH and soil water content.The effect of paspalum natatumn was better than that the control of gardenia,and it was significantly different from that in the 0-20 cm soil layer(p<0.05).The effect of gardenia on soil water content was better than that of paspalum natatumn and there was significant difference between 20-40 cm soil layer and control(p<0.05).The gardenia and paspalum natatumn resistance control arrangement can increase the total carbon content of soil.Compared with the contrast,the soil total carbon content was increased by 37.05%,which was better than that of the gardenia.In addition,the effect of paspalum notatum on improving soil total nitrogen content was significant.The contents of DOC,DTN and DON in the contrast zone were 73.33%,6.63%and 77.06%.The paspalum notatum can increase soil DIN by 6.7%.Gardenia control zone can increase the available nitrogen and available potassium content in 20-40cm soil layer,and the gardenia control arrangement can improve the available nitrogen and available potassium content in 0-20cm soil layer.The gardenia block and the paspalum notatum can reduce runoff and sediment loss.Compared with the contrast,the paspalum notatum resistance zone reduced the flow loss of 12.1%and the sediment loss of 28.9%,which was better than gardenia.(2)In the study of the chestnut forest,the control model of daylily and micro-topography could improve soil pH and soil water content.The control effect of daylily is better in improving soil pH value.In the 0-20cm soil layer,the daylily was significantly improved the 20-40cm soil layer,micro-topography mode can improve soil moisture content.In addition,the micro-topography mode can improve soil total nitrogen and total carbon content.The content of DTN in the contrast can increase the content of soil DTN.The increase by 79.25%and 113%in 0-20cm and 20-40cm soil layers are better than that in micro-topography mode.The control of DIN and DON in chestnut forest soil was significant.The micro-topography mode blocked the soil DOC by 145%.In the 0-20cm and 20-40cm soil layers,the micro-topography mode could increase soil available nitrogen content by 60.07%and 62.55%,which was better than that of the daylily.The arrangement of the daylily can improve the content of available potassium in 0-20cm soil layer.In the 20-40cm soil layer,the two kinds of resistance control mode to block potassium loss were not obvious.Both control modes can reduce the runoff and sediment loss of chestnut forest.Compared with the control,the micro-topography mode can reduce the runoff by 17.9%and the sediment loss by 15.4%.However,there was no significant difference between the two control modes(p>0.05).(3)In the study of ginkgo forest,the myrtle and Taiwan-daylily arrangement can improve the pH and the soil moisture.The control of myrtle was better than the Taiwan-lily control zone,with an increase of 3.8%.In addition,Taiwan-daylily control zone can improve the soil total nitrogen content.Myrtle control zone can improve the soil total carbon content.The soil content of soil in the 0-20cm and 20-40cm soil layers was increased by 77.45%and 76.48%.Taiwan-daylily control zone can increase the content of DTN in 20-40cm soil;the maximum is 33.47mg/kg.The content of DTN in 0-20cm soil was increased by 79.25%compared with the contrast.In addition,Taiwan-daylily control zone can improve the soil DIN content.Myrtle zone can improve the soil DON.Taiwan-daylily can improve the soil available nitrogen content,the maximum was 90.4mg/kg.The content of available potassium in soil was increased by 33.73%.Both plant resistance bands could reduce the runoff and sediment loss of ginkgo forest.However,there was no significant difference in statistics(p>0.05).The 16.4%of runoff can be reduced by comparison with contrast.Taiwan-daylily arrangement can block sediment loss by 65%.