Pilot crop rotation and fallow should focus on "hiding grain in the land"

In the explanation of the proposal of the 13th five-year Plan, "exploring the pilot system of cultivated land rotation and fallow" is listed as several issues that need to be emphasized, in which it is clearly pointed out that after long-term development, the intensity of development and utilization of cultivated land in China is too high. the serious overdraft of soil fertility in some places, soil erosion, serious over-exploitation of groundwater, soil degradation and aggravation of non-point source pollution have become prominent contradictions restricting the sustainable development of agriculture. At present, domestic grain production has continued to grow, stocks have increased, and imports have also increased substantially. Taking advantage of the ample food supply in domestic and foreign markets at the present stage, cultivated land rotation and fallow cultivation has been carried out in some areas. it is not only conducive to the cultivation of cultivated land and the sustainable development of agriculture, but also conducive to balancing the contradiction between grain supply and demand, stabilizing farmers' income and reducing financial pressure.

There has always been a system of crop rotation and fallow. In the Qi Min Yao Shu of the Northern Wei Dynasty, there are such records as "the grain field must be changed every year", "hemp wants to get good land without ruins", "every valley field, mung bean and adzuki bean bottom are above, hemp, millet and so on." turnips, soybeans and other records, it can be seen that China's ancient farming culture has attached importance to the traditional wisdom of land rotation and fallow. Rotation fallow is also a common cultivated land protection measure in foreign countries. In the United States, facing the challenge of food oversupply and the urgent need to improve the ecological environment, the Agriculture Act of 1985 decided to implement fallow protection projects and carry out planned fallow in the following year; in the Agricultural Act amended in 2002, the maximum amount of fallow is 230 million mu, accounting for about 16% of the total area of arable land. In Europe, "two-nursery rotation" appeared as early as the 8th century, and later appeared "three-nursery" and "four-nursery", such as the "four-nursery" in Norfolk, England, which divided the cultivated land into four areas. In turn, red clover, wheat (or rye), forage turnip or sugar beet, two-rowed barley (or red clover) can be planted in turn. If fallow is needed, one of the areas can no longer grow crops.

Exploring the system of cultivated land rotation and fallow should be based on the guarantee of national food security. Although China has had a bumper harvest for many years, and the total grain output reached 1.2142 trillion jin in 2014, stable at more than 1.2 trillion jin for two consecutive years, some experts predict that by 2020, China's annual grain demand will be about 1.4 trillion jin, and there is still a shortfall of about 200 billion jin. Grain output can be adjusted according to market demand, and grain production capacity must be steadily increased, that is to say, according to the size of market demand, grain planting area can be adjusted through measures such as crop rotation and fallow, but the area of cultivated land, the quality of cultivated land and agricultural technology must be maintained at a high level, and when grain production needs to increase, it must have the ability to produce so much grain.

To explore the system of cultivated land rotation and fallow, it is necessary to accurately identify the "three fields". Fields with tight resources, deteriorating environment and overcapacity. After years of planting, the land with over-exploitation of groundwater resources, the decline of soil fertility and the increase of soil salinity can be called resource-tight fields. For example, due to the over-exploitation of groundwater in some areas of the North China Plain, a "groundwater funnel" has been formed, which can reduce the planting area of crops with large water consumption, promote drought-resistant crops or varieties, or set aside a certain proportion of fallow. In many places, due to excessive or unbalanced fertilizer input, beyond the capacity of the soil environment, resulting in quality deterioration, heavy metal pollution, ecological degradation and other cultivated land environmental problems, the principle of "different proportion of nutrient demand of different crops" can be used to adjust and improve soil quality.

To explore the system of rotation and fallow of cultivated land, we should give appropriate subsidies to farmers. If the pilot crop rotation and fallow system is to be carried out in an orderly manner, we must give full play to the guiding role of the subsidy policy. At present, China is gradually expanding the scale and scope of the "green box" subsidy policy, adjusting and improving the "yellow box" subsidy policy. Although fallow subsidies are listed in the "yellow box" scope of the WTO, fallow subsidies are included in the "blue box" policy to meet the requirements of the European Union and the United States. Not bound by the Agreement on Agriculture. When implementing fallow plans in the United States, France and other countries, most fallow plans are subsidized by the government and farmers participate voluntarily. For example, the subsidies provided by the United States mainly include two aspects: on the one hand, land rent subsidies, which evaluate and determine an annual land rent subsidy price according to the relative productivity of the land and the local dry land rent price; on the other hand, share with farmers the cost of implementing vegetation protection measures, and provide farmers with cash subsidies of no more than 50% of the cost according to their cost of implementing recommendation, tree planting and other vegetation protection measures.

In short, China's exploration of cultivated land rotation and fallow system is complex, not only to ensure the safety of food rations, but also to hide grain in the land; not only to consider labor input, but also to ensure farmers' income; not only to balance the supply of all kinds of agricultural products, but also to find the different crux of cultivated land. Therefore, the red line of cultivated land must be firmly guarded and pilot projects must be carried out in an orderly manner.