| ①Geostatistics combined with GIS was used to analyze the spatial variability of watershed soil nutrients in topsoil (0-20 cm) in Maliu, Jiangjin. The result showed that the variation coefficient of soil nutrients in the watershed area had a tendency that available P>available K>available N>total P>organic matter>total N>total K. Among the nutrients,available P expressed strong variability, pH and total K showed slight variability while the others all expressed medium variability. The range of soil was between 133 to 942 meters, so the 100-meter sampling internal of this research maked it possible to apply the evaluation of soil spatial variability to this area. The distribution of soil pH was the most regular, followed by that of total N, available N and available K and that of total P showed little rule. The spatial variability of soil nutrients influenced more by random factors than by structural factors and the effect of human factors was more than that of intrinsic attribute. The result of this research can provide scientific instructions for the management of soil nutrients in the area.②Samples in this research distribute were at elevations between 300 and 400 meters and slope at 2 degrees to 25 degrees. Soil pH had significant correlation with elevation while there was insignificant correlation between other elements and topographic factors. Organic matter showed significant positive relation with clay and evident negative relation with sand, while total N had extremely significant positive correlation with clay, extremely negative one with sand and evident negative one with silt. Available P had significant positive relation with clay and extremely negative correlation with sand while the others showed no relationship with sand, silt or clay.The influences of three kind of utilizations of land to the content of soil nutrients were different and none of them had reached evident level according to the analysis of variance. There was significant correlation among all the nutrients:pH showed positive relationship with total K and evident negative one with other nutrients, especially, the relationship with available N and available K was evident; total P and available P had extremely significant correlation with total K; organic matter had positive relation with all other nutrients among which the one with available P was evident and the one with total N and available N was extremely significant;total N and total P had extremely positive significant correlation with available N and available P, respectively and the research also indicated that the supply of available K was far from enough.③There was evident correlation among soil N, P and K and the research of no-till efficient planting mode in pepper covering area showed that available N,available P and available K were all necessary for plants.Comparing with traditional fertilization treatments, adding the content of potash fertilizer could obviously increase the production of pepper and improve the efficiency of N fertilizer and P fertilizer. The best proportion of N, P, and K was 1:0.75:0.75 and if fertilized with this mode, pepper's production will increase by 36%, based on which there would be no influence on the production if fertilized with B and Zn while the fertilization of organic fertilizers would increase its production by 14.8%.Based on fertilization tests of different match and ratio, the controlled release fertilization could lead to significant increase of pepper yield. Proper fertilization of total content of N, P and K was around 1050 kg/hm2 which converting to inorganic and organic controlled release fertilizer was 2280 kg/hm2 and 3495 kg/hm2 respectively.④Compared with other two pruning methods, the work of renewal pruning was 190.70% and 72.41% more than that of thinning-out cut and shortening cut respectively but the time renewal pruning took was just 28.74% and 44.64% of that thinning-out cut and shortening cut took respectively and the production rate of renewal pruning was 69.89% and 19.70% higher than that of thinning-out cut and shortening cut respectively. Four consecutive years'monitoring of pepper production showed that renewal pruning contributed to stable yield and the annual mutation of production was 40%～50% lower than that of thinning-out cut and shortening cut. The efficiency of picking all broken branches at one time was obviously increased compared with traditional method and the collection quantity reached 35.5 kg/person.day which was about twice that of picking on trees and the cost of collecting also decreased to half the cost picking on trees took. The rate of damage to oil glands caused by picking all broken branches at one time was 32% of that of picking on trees, meanwhile, the intensity of labor changed from high to low and injury people may get when working changed from serious to slight. The integrated harvest technology can decrease the consumption of both manpower and resources as well as the side-effect caused on the picking worker.⑤The content of organic N, organic P and organic K in pepper branches was 2.01%,0.24% and 1.12% respectively and that of microelements such as Ca, Mg, Fe, Mn an Zn was rich which equaled to the fertilization of 191.17g urea,87.00g calcium superphosphate and 98.00g K2SO4 when calculated as 25kg branches per plant so that it could decrease the application rate and supply essential microelements for plants. The regression analysis indicated that with time going on, the residue and decomposability of branches changed linearly and the correlation coefficients were 0.9260 and 0.9263 respectively but the residue was decreasing while the decomposability was increasing. After ninety days, the breaking down of branches reached its top. The content of salvianolic acid presented exponential law with a correlation coefficients of 0.9124 and decreased fastest within the first ten days, followed by the second ten days and gradually got slower. After twenty days, when the content of salvianolic acid decreased to about lmg/g, putting the branches over the tree disks about 15cm～20cm could fertilize the crops and improve their ability of resisting drought and preserving water.The bulk density of soil covered by straw and pepper branches was respectively 10.13% and 16.46% lower than that of soil covered by nothing and the porosity of them was respectively 12.63% and 20.52% higher than that of soil covered by nothing. The variation of organic matter, available N, available P and available K in soil covered by pepper branches and leaves was the highest, followed by in soil covered by straw and the two were all higher than that in soil covered by nothing.The variation of organic matter, available N, available P and available K in soil covered by pepper branches were respectively 96.15%, 21.06%,67.50% and 27.19% higher than in soil covered by nothing and were 10.27%,6.86%,38.61% and 17.59% higher than in soil covered by straw, which could indicate that covering pepper branches and leaves over soil could improve its physical and chemical properties significantly.The runoff depth,runoff coefficients and sediment concentration in no-tillage cultivation mode all showed decreasing trend when under the same rainfall level with traditional pattern. The loss of rainfall decreased by 12.55%～19.75% and the loss of soil decreased by 19.21%～29.63% meanwhile the inorganic and organic compounds erosion were both slighter than in traditional pattern. If under different rainfall level, the runoff depth, runoff coefficients, sediment concentration as well as inorganic and organic compounds in no-tillage with straw mulch pattern all increased but the range was smaller than in traditional mode and were more effective in reducing erosion of the soil and conserving water and soil.⑥The test of pepper no-tillage cultivation mode showed that compared with conventional planting pattern and formulated fertilization,no-tillage cultivation saved 345 workday/(hm2·a) and 20700 yuan/(hm2·a) but the input materials including fertilizers and pesticides increased slighted. The pepper yield in no-tillage cultivation mode was as much as that in formulated fertilization and 53.39% higher than that in conventional planting mode, meanwhile, its net profit was 159.02% higher than conventional planting's and 28.20% higher than that of formulated fertilization. |
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