| Cultivated land productivity evaluation contributes to learn the cultivated land resource situation and productivity status of the study area, and provide the basis for agricultural development and policy making. There are already forming some mature cultivated land productivity evaluation methods that has been applied in many areas both at home and abroad. Because of the change of study area and scale, cultivated land productivity evaluation studies should consider the characteristics of the study area and it is hard to directly transplant the research results from other areas. IF different methods are used in one study area, we may get different results. The paper focuses on provincial cultivated land evaluation study and select Henan province as the study area. This paper mainly improves the expression methods of soil map, establishes index system and model of cultivated land evaluation in Henan province, and compares the influences of the evaluation methods for evaluation of cultivated land. In order to make the provincial cultivated land evaluation smooth and improve the accuracy of it. The main conclusions are as follows:1. Establish the database of cultivated land resource and study evaluation index system in Henan province. The study collects the data about cultivated land resources and organizes them, and then establishes the database of cultivated land resources in Henan Province using GIS and some another methods, including soil information(soil map, arable layer texture map, soil obstacle information in detail, a large number of soil nutrient points), climate information, irrigation condition, drainage condition, geomorphic types and so on. According to the characteristics of cultivated land resources in Henan Province, the study sets up evaluation index system and model using a total of 11 indexes, including organic matter, available p, available k, arable layer soil texture(0~20 cm of soil texture), soil profile properties(20~100 cm soil profile properties), irrigation assurance, drainage capability, the degree of difficulty of mechanical work(represented by the geomorphologic types), light intensity, greater than or equal to 10℃ accumulated temperature, annual average rainfall.2. Study soil profile expression that is suitable for provincial cultivated land productivity evaluation. On the basis of the original soil map, combined with the typical soil profile, the study sets up new soil map that mainly expresses soil barrier layer information. According to barrier type, barrier location and barrier intensity, soil profiles include 32 types, reflecting the influence of soil on cultivated land productivity. The new soil map makes up for the disadvantages of the original map with so many soil types(428), as well as the difficult judgment of cultivated land productivity based on soil genus. It is smooth for cultivated land evaluation work that the study improves the expression method of soil map, while it improves accuracy of the cultivated land evaluation result.3. Compare different Soil Fertility Calculation Mode. In Huaibei area, the study gains cultivated land fertility index by cultivated land fertility evaluation and natural index by agricultural land classification. The correlation coefficient of grain yield and soil fertility index is high, as well as natural index, so both of the results of the evaluation can be used as a further study. The process of farmland classification is more complicated than the process of cultivated land fertility evaluation. Compared the results of two methods, natural index is easier to distinguish level than cultivated land fertility index. Two results present small discrepancy in plain, large difference in hilly area, small difference in North Henan and East Henan and large difference in South Henan and West Henan. On the whole, the correlation of natural index and grain yield is better than the correlation of cultivated land fertility index and grain yield. |
PDF Full Text Request