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Evaluation of the healthy productivity of cultivated land in China, analysis of key problems of different regions that endangers cultivated land health is of great significance to explore sustainable cultivated land utilization path and safeguard national food security and ecological security. The evaluation of cultivated land healthy productivity should be executed base on integration of existing evaluation indicators system and evaluation method achievements and clarification of key factor states and driving processes that affecting cultivated land health from the perspective of cultivated land components. And interaction characteristics between cultivated land health and cultivated land productivity should be analyzed by coupling them with each other. In this paper, we selected 65 counties (cities) nationwide as research regions with considering the difference of climate conditions in different regions of China, and used 5 categories of indicators including topographic characteristics, soil properties, tillage conditions, environmental conditions and biological characteristics to present the cultivated land health status. And on that basis, we defined critical health threshold and critical sub-health threshold of different indicators by analyzing counties’ indicator standard deviation convergence characteristics and scoring rules. We divided all pilot counties into three statuses: Health, sub-health and unhealth, and analyzed spatial distribution features of counties with different health status. Furthermore, regional climate conditions indicator, cultivated land natural conditions indicator and tillage technique level indicator had been synthetically integrated to evaluate the productivity of cultivated land, and regional cultivated land health-productivity interaction characteristic had been analyzed. Experimental result showed that counties whose cultivated land in sub-healthy or unhealthy status expressed significant regional features, and the key factors of limiting cultivated land health were different among pilot counties. On the one hand, the sub-health status cases caused by inferior farming conditions indicator were more common (accounting for nearly 40% of pilot counties) than other indicators, which was not only manifested by serious fragmentation of cultivated land and imperfect farmland infrastructure, but also reflected the urgent requirement for promoting high-standard farmland construction. On the other hand, the form of biological characteristics was severe, indicating that under the interaction of climatic conditions, soil structure and tillage technology, the ability of cultivated land to guarantee the healthy growth of animals was facing degradation. Furthermore, through coupling analysis of cultivated land health and cultivated land productivity, we divided the cultivated land healthy productivity characteristics of pilot counties into six categories: “health-high productivity”, “health-low productivity”, “sub-health-high productivity”, “sub-health-low productivity”, “unhealth-high productivity” and “unhealth-low productivity”, and respectively analyzed the regional farmland protection directions for each category. “Sub-health/unhealth-high productivity” type was widely distributed, which was the core region for implementation of “storing grain on land and storing grain in technology” strategy in China. Therefore, it is necessary to give consideration to the health and productivity of cultivated land in this region, and strengthen the research and practice on methods to improve the health of cultivated land. This study provides scientific basis for improving cultivated land healthy productivity and provides effective support for designing protection paths of cultivated land resources in different regions. [ABSTRACT FROM AUTHOR]

Drought has become a problem that is universally faced by global terrestrial ecosystems. Northeast China is dominated by a temperate monsoon climate and located in an area sensitive to global climate changes, and one of the main impacts of climate changes in Northeast China is manifested as drought in growing seasons. The drought area has a gradual increase trend, and drought has become the main agro-meteorological disaster in this region which is also the main maize planting area in China. Drought normalization seriously restricts the stable development of maize production in Northeast China. So in this paper, we took spring maize in Liaoning Province as an example and made clear the drought variation characteristics in different growth stages by using the data of MODIS, FY-3A, relative soil moisture and growth stages and the methods of RS, GIS and statistical analysis. Then we analyzed the correlation between multi-time scale remote sensing indexes and relative soil moisture in different soil depth, and established the remote sensing monitoring index set and models of relative soil moisture for each growth stage and soil depth. The accuracy of the monitoring models was verified and the application research of monitoring the drought of spring maize in Liaoning Province was studied. The results showed that: From 1993 to 2012, drought occurred in each growth stage of spring maize in Liaoning Province and the highly frequent drought occurred in the period from 1999 to 2002. The drought grade in each year was mainly light drought, and the drought was the most serious at milk stage, followed by heading stage. There was no significant correlation between the monitoring indexes and relative soil moisture at sowing and emergence stage, but there was a significant or extremely significant correlation between them at three-leaf and maturity stage. The monitoring index LSWI (land surface water index) had a strong ability to monitor relative soil moisture, followed by WI (water index). Multi-index coordination could improve the monitoring ability of relative soil moisture by remote sensing means, and the monitoring ability at 10-day scale was generally higher than that at 5-day scale and 20-day scale. Based on the monitoring models of soil relative humidity, the drought condition of partial growth stages and soil depth from 2001 to 2004 was monitored. The overall monitoring accuracy was 73.32%, in which the monitoring accuracy of jointing and three-leaf stage was more than 85%. The dynamic monitoring of drought grades in different growth stages in 2000 was realized. The monitoring results were consistent with the agro-meteorological observation records in terms of the growth stages and space. This study would be very significant to improve the capacity of disaster prevention and mitigation by monitoring spring maize accurately and synchronously on a large range. [ABSTRACT FROM AUTHOR]

Evaluation of the healthy productivity of cultivated land in China, analysis of key problems of different regions that endangers cultivated land health is of great significance to explore sustainable cultivated land utilization path and safeguard national food security and ecological security. The evaluation of cultivated land healthy productivity should be executed base on integration of existing evaluation indicators system and evaluation method achievements and clarification of key factor states and driving processes that affecting cultivated land health from the perspective of cultivated land components. And interaction characteristics between cultivated land health and cultivated land productivity should be analyzed by coupling them with each other. In this paper, we selected 65 counties (cities) nationwide as research regions with considering the difference of climate conditions in different regions of China, and used 5 categories of indicators including topographic characteristics, soil properties, tillage conditions, environmental conditions and biological characteristics to present the cultivated land health status. And on that basis, we defined critical health threshold and critical sub-health threshold of different indicators by analyzing counties’ indicator standard deviation convergence characteristics and scoring rules. We divided all pilot counties into three statuses: Health, sub-health and unhealth, and analyzed spatial distribution features of counties with different health status. Furthermore, regional climate conditions indicator, cultivated land natural conditions indicator and tillage technique level indicator had been synthetically integrated to evaluate the productivity of cultivated land, and regional cultivated land health-productivity interaction characteristic had been analyzed. Experimental result showed that counties whose cultivated land in sub-healthy or unhealthy status expressed significant regional features, and the key factors of limiting cultivated land health were different among pilot counties. On the one hand, the sub-health status cases caused by inferior farming conditions indicator were more common (accounting for nearly 40% of pilot counties) than other indicators, which was not only manifested by serious fragmentation of cultivated land and imperfect farmland infrastructure, but also reflected the urgent requirement for promoting high-standard farmland construction. On the other hand, the form of biological characteristics was severe, indicating that under the interaction of climatic conditions, soil structure and tillage technology, the ability of cultivated land to guarantee the healthy growth of animals was facing degradation. Furthermore, through coupling analysis of cultivated land health and cultivated land productivity, we divided the cultivated land healthy productivity characteristics of pilot counties into six categories: “health-high productivity”, “health-low productivity”, “sub-health-high productivity”, “sub-health-low productivity”, “ill-health-high productivity” and “ill health-low productivity”, and respectively analyzed the regional farmland protection directions for each category. “Sub-health/ill-health-high productivity” type was widely distributed, which was the core region for implementation of “storing grain on land and storing grain in technology” strategy in China. Therefore, it is necessary to give consideration to the health and productivity of cultivated land in this region, and strengthen the research and practice on methods to improve the health of cultivated land. This study provides scientific basis for improving cultivated land healthy productivity and provides effective support for designing protection paths of cultivated land resources in different regions. [ABSTRACT FROM AUTHOR]