Why is arable land quality survey, monitoring and evaluation so significant?
Arable land is a precious and limited natural resource. Arable land quality bears on national food security, the quality and safety of agricultural products, and ecological security, and is a necessary foundation for safeguarding sustainable socioeconomic development and meeting the people's ever-growing material needs. China's arable land area is shrinking rigidly, the population is growing rapidly, and the contradiction between grain supply and demand is becoming increasingly prominent; improving the quality of China's arable land is a strategic decision for national food security. However, the basic fertility of China's farmland is about 20 percentage points lower than that of developed countries; highly intensive farmland cultivation, and high-intensity, high-input utilization methods, especially the intensive model of unbalanced nutrients, have not only led to the degradation of farmland fertility but also caused a number of ecological and environmental problems; this has led to relatively large fluctuations in China's grain production and prevented the potential of high-yield crop varieties from being brought into full play. Therefore, grasping the characteristics and patterns of arable land quality change across different regions and under different utilization methods, and conducting long-term monitoring, evaluation and early warning of arable land quality, is of very great significance for improving China's arable land quality, guiding arable land quality management, and ensuring national food security and sustainable agricultural development.
In China, degradation phenomena caused by unreasonable utilization, such as secondary gleyization, secondary salinization, desertification, nutrient depletion, soil erosion and environmental pollution of arable land, have already become very serious. Transforming the quality traits of degraded arable land is an arduous task that requires complex technology, substantial investment and long-term labor. In the short term, the quality traits such as productivity of reclaimed arable land cannot compare with high-quality arable land. However, the dynamic monitoring of arable land quality currently carried out generally takes place after arable land quality degradation has occurred, by which time arable land production performance and arable land utilization benefits have already suffered a certain degree of harm. By conducting arable land quality monitoring, however, it is possible to dynamically monitor arable land quality, provide early warning of change trends, and adopt preventive countermeasures according to the early warning, so that arable land quality can be maintained at a relatively high level with only relatively little investment. Therefore, arable land quality monitoring is an important foundation for carrying out targeted arable land quality construction and raising the goals and benefits of arable land quality construction.
Arable land quality monitoring and evaluation is a basic, long-term task. In order to fully grasp the state of China's arable land quality and the dynamic change patterns of soil fertility, since the 1980s agricultural departments at all levels across the country have established a batch of long-term positioned monitoring points for arable land quality at different levels. According to incomplete statistics, there are about 3,000 provincial-level monitoring points, 2,000 prefecture-level monitoring points and 9,000 county-level monitoring points that have been maintained long term across the country; these long-term positioned monitoring efforts play an important role in finding out the baseline and change trends of China's arable land quality. However, these monitoring points are too few in number, and the monitoring items focus on soil fertility and productivity, with insufficient attention to soil environmental factors. Therefore, the Ministry of Agriculture will recently standardize arable land quality monitoring and evaluation and has issued the Measures for Arable Land Quality Survey, Monitoring and Evaluation. This round of arable land quality monitoring and evaluation work will, on the basis of these efforts, further expand the monitoring points and monitoring content, carry out networked monitoring and early warning of arable land quality change in China, advance the construction of a long-term monitoring network for China's arable land quality change, promote the standardized collection of monitoring data and the in-depth analysis of large amounts of data, make full use of long-term positioned soil and fertilizer experiments and the "3414" experiments of soil testing and formulated fertilization, carry out research on the evolution patterns of arable land fertility, driving factors and their coupling relationship with productivity, and put forward targeted countermeasures, measures and suggestions for soil fertility building and improvement and scientific fertilization for China's medium- and low-yield fields, so as to provide basic data and a theoretical basis for achieving sustained increases in China's grain output and improvement of arable land quality.
The Measures for Arable Land Quality Survey, Monitoring and Evaluation (hereinafter referred to as the Measures), in the form of departmental rules, fills the gap in dedicated legislation on arable land quality management and protection at the national level, and has the characteristics of being systematic, comprehensive, dedicated and operable. The Measures provide an important basis for agricultural departments at all levels to improve the arable land quality survey and monitoring system, carry out arable land quality survey, monitoring and evaluation, and release arable land quality information, and are of milestone significance for raising the level of China's arable land quality management and protection under the new situation.
The Measures will promote the management of arable land quality survey, monitoring and evaluation data, safeguard the integrity, authenticity and accuracy of the data, promote research on arable land quality, put forward countermeasures and measures for the protection and improvement of arable land quality, effectively drive new achievements in China's arable land quality management and protection, and advance the implementation of the strategy of "storing grain in the land and storing grain in technology"!