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The enhancement of cultivated land quality is an important measure to improve the production capability and ensure the food safety. At the construction course of cultivated land quality informatization, novel methods and techniques are promising to improve the current working pattern as well as raise the efficiency of cultivated land quality management. Irrigation guarantee capability is an important element of cultivated land quality monitoring, evaluation and construction. Evapotranspiration (ET) derived from remote sensing can be used for rapid monitoring of irrigation guarantee capability of cultivated land at the regional scale. In order to improve the acquisition efficiency of the regional cultivated land quality monitoring, a new evaluation method was proposed for irrigation capability evaluation of cultivated land based on Moderate Resolution Imaging Spectroradiometer (MODIS) ET products. First, in order to reduce the representative errors of meteorological data, the relationship between the monthly potential evapotranspiration (PET) parameter derived from MODIS evaporation products and the reference crop evapotranspiration (ET0) calculated from observed meteorological data with the Penman-Monteith (P-M) formula was analyzed. The continuous ET0 in space was obtained from the regression model. And then, water requirements for crop were obtained by the map of crop type from the classification of Landsat TM data and space-continuous ET0. Furthermore, the annual water requirement was calculated according to the difference of the water requirement for crop and the rainfall which was effectively consumed by crop. Additionally, based on the regional water balance principle, the actual quantity of irrigation was obtained from the difference of actual evaporation derived from ET products of MODIS and effective rainfall. The evaluation index of irrigation guarantee capability is defined as the ratio of the annual irrigation requirement and the actual quantity of irrigation, and used for the monitoring and evaluation of cultivated land irrigation guarantee capability. Finally, application and analysis were conducted in Hengshui City, Hebei Province, China. The R2 of the regression model between the PET and ET0 from meteorological stations reached 0.89. And the calculated results of the evaluation index of irrigation guarantee capability from 2005 to 2012 accurately reflected temporal-spatial variations for the cultivated land irrigation capability. Meanwhile, the comprehensive evaluation of irrigation capability, which was from the supervised classification results based on actual survey, had a good agreement with the classification results of irrigation probability in the gradation on agriculture land quality which had been updated in 2012. The area with no grade difference was up to 37% of the total cells, 38% of the study area had one-grade difference, and the area with two-grade difference was 19% of the study area. The area with three-grade difference only accounted for 6%. The grade difference of more than 75% of the cultivated land was less than one grade. Errors were mainly concentrated in the cultivated land around the city, because the MOD16A2 product with 1-km resolution was inadequate to accurately represent the information of that complex planting structure of cultivated land, and this problem would be solved with the development and improvement of remote sensing earth observation systems with higher resolution. The evaluation index of irrigation capability proposed in this paper has the advantage of clear physical meaning and easy data accessing. The experiment results indicate that the method can meet the needs of the regional cultivated land quality monitoring and evaluation. [ABSTRACT FROM AUTHOR]

The results of cultivated land quality gradation are made of the results of county, provincial, national levels. The results at the provincial level are integrated by the results at the county level. Provincial integration is an essential link in cultivated land quality grading work. The traditional provincial integration methods excessively depend on the provincial integration base map, which makes the integration efficiency low. Moreover, the quality of integration work completely depends on the quality of integration base map. Based on these defects, this paper comes up with a method that uses the grid instead of the integration base map. In provincial integration work, we need to build traceability relation between county units and provincial units. It requires all county units can find provincial units and all provincial units have their corresponding county units. Moreover, there is a principle we have to abide by: the ownership, the land type and the grade should be coincident between the county units and corresponding provincial units. That is "ownership-land type-grade" coincident principle. The purpose of this method is to make spatial distribution of provincial cultivated land quality is similar to that of the county when abiding by this principle. First we need to classify the county results according to "ownership-land type-grade". Then we determine the corresponding grid category according to the area dominant principle. Through the spatial nearest neighboring method, we find the grid unit closest to the unit at the county level to build "Grid-County grading unit" relations. But maybe there are some categories which can't be found in the provincial grids. Based this situation, the barycenter of the missing category was firstly calculated, then an uncultivated area grid closest to the barycenter was searched out, and lastly this grid was marked as the missing category. The grid coding method proposed in this paper stipulates that grid code is formed by county's administrative code, the grid rank, quality gradation and land class code. The length of the code is 21. At last, this paper uses the mean center and standard deviational ellipse to test the similarity of the spatial distribution of cultivated land before and after integration. This paper takes Daxing district, Bejing as a study area. By "ownership-land type-grade", there are 8 categories in Daxing. According to the distribution of cultivated land in Daxing district, 688 valid cultivated land grids were finally determined. Using the method in this article, we completed the integration at the provincial level for Daxing. After test, it showed that the difference of mean center between provincial grid results and county results is only 405.6 m, and the difference of distribution direction is only 0.34°, which means that this method can ensure the consistency of spatial distribution of cultivated land at different levels. Compared with the method which depends on the integration base map, the method based on grid doesn't make base map, reduces workload and improves work efficiency. This method orientates the provincial cultivated land into each grid and codes for these grids. Through grid code, we can quickly search cultivated land quality in the corresponding position, which is very convenient for both management and application. [ABSTRACT FROM AUTHOR]

Since the numbers and capacities of dairy cattle farms are increasing with every passing day, computer aided studies for the management of these farms become more important and are widely used in daily life. In this study, we assessed the potential of Xtion as a point cloud data acquisition system for the body measurements of Holstein cows in the context of dairy cow conformation. For this purpose, we selected Xtion for point cloud data acquisition and chose a dairy cow model and a dairy cow as the experimental subjects. In an indoor environment, three dimensional laser scanners with high precision were employed to get point cloud data of the cow model as comparison data, and Xtion was used for acquiring point cloud data at different distances away from the cow model as test data. After aligning the comparison data and test data by using commercial point cloud processing software, statistical errors between comparison data and test data including positive maximum distance, negative maximum distance, positive average distance, negative average distance, standard deviation, and RMS error were calculated by the professional point cloud software in order to quantitatively analyze the precision and density of point cloud data from Xtion at different distances. The test results indicate that the errors almost increased linearly with increasing of the distance between Xtion and subject. The average errors were less than ±5mm on the condition that the distance from Xtion to the subject were between 0.6m and 1.2m. The average errors were less than ±10mm on the condition that the distance between Xtion and the subject were between 1.2m and 1.8m. Maximum errors were always less than ±20mm. The density of point clouds decreased exponentially with increasing of the distance from Xtion to the subject to such an extent that body measurements were impossible to get on account of missing the mark points on the body. These results imply that the appropriate distance between Xtion and a cow is between 0.6m and 1.2m. Under the dairy cow breeding environment, body measurements including chest width, thurl width, rear leg side view, front nipple length, rear udder width, and rear udder height of cows were first determined manually, by direct measurement. Then we used Xtion to acquire point cloud data at a distance of less than 1.2 meters from the cow. Visualization of the point cloud data and interactive measurement of the cow body based on point cloud data from Xtion were performed by Meshlab so as to qualitatively analyze the sunlight and surface materials’ influence on the quality of point cloud data acquired from Xtion under dairy farm conditions. The results indicate that Xtion failed to give normal operation under the sunlight due to the presence of the IR rays in the sunlight. Point cloud acquisition from Xtion may have some small holes due to the material and appearance of a live cow body. The relative errors of comparing the body measurements obtained by Meshlab with the manual measurements were less than 10%, which indicates that Xtion is appropriate for body measurements of Holstein cows. [ABSTRACT FROM AUTHOR]