In the northeast region of China, there is a piece of fertile soil distributed in the vast northeast land in a belt, covering an area of 70,000 square kilometers.
That's black soil.
The surface layer of the black soil is black and fertile, and the natural vegetation is grassland meadow plants, mainly mesophytic meadow plants, and xerophytic grassland plants can be seen in well-drained places. Due to the short warm season and the long and severe cold cold season, the microbial activity intensity of the soil is not large, and a large amount of organic matter is difficult to decompose quickly, and is mostly converted into black humus, thus forming a surface soil with high humic content.
The topography of the black soil area is mostly the high plain and piedmont flood plain that rises intermittently in the middle of the modern neotectonic movement and is cut to varying degrees: in the gentle terrain, the thickness of the black soil layer is generally 40 cm to 100 cm; In areas with large slopes, the thickness of the black soil layer is about 20 cm to 30 cm.
Thin layer of black soil (black soil layer less than 30 cm).
Medium-thick black soil (30 cm to 60 cm in the black soil layer).
Thick layer of black soil (black soil layer greater than 60 cm).
The organic matter content of the black soil layer in most black soils is 3% to 6% (at present, the organic matter content of the black soil layer in cultivated land is mostly 15%~4.around 5%).
The soil organic matter content of the tillage layer in the north-eastern part of the country is 1 per year5%~2.6%, south to 05%~0.7% rate decrease. (After reclamation, the plant residues in the black soil are rapidly decomposed under the action of microorganisms, the conditions for the accumulation of organic matter are destroyed, and the soil organic matter content decreases rapidly.) From natural soil to relatively stable cultivated soil, it takes 30 years of land use transition).
The average annual rate of decline of soil organic matter content was 0About 1%, the impact on crop yield is more significant (according to statistics, the content of soil organic matter in the cultivated layer decreases by 05%, and crop yields are reduced by 15%. In general, after 50 years of black soil reclamation, the decline rate of soil organic matter is stable at 006% or so. ）
The decrease of organic matter content in the black soil layer will lead to the "in-situ degradation" of the black soil layer.
In sloping farmland and wind erosion areas, soil degradation after migration of black soil layers due to water flow and wind drive is called "migration degradation". It is estimated that the rate of loss of black soil layer in sloping cultivated land in the black soil of Northeast China is 05 mm 15 mm.
In recent years, the black soil conservation model with straw deep mixed returning as the main measure has been adopted for the medium and thick black soil layer, and the black soil cultivation model with straw and organic fertilizer deep mixed returning to the field has been adopted for the shallow black soil layer. A corrosion control and fertilization model was established for black soil slope cultivated land, and a conservation tillage model was established for black soil wind erosion area.
Taking Heilongjiang Province, which has the largest black soil area, as an example, multi-year monitoring shows that the average thickness of the cultivated layer in the dry land in the black soil area is 198 cm deepened to 233 cm.
Rice, grains, and other grains grown in the black soil are more nutritious and flavorful than ordinary lands, and they also have a unique taste. One of the specialties is organic corn. But did you know that there are actually 3 types of organic corn, including organic yellow waxy corn, organic black waxy corn, and organic white waxy corn.
The organic planting base of Pinsenhuo cooperation has 41 ° north latitude China's ** corn belt - Jilin Tonghua, the local temperature difference between day and night is 15 °, the winter is long and the summer is short, with the nourishment of the fertile black soil, after 2400 hours of sunshine, rain and dew, solar terms, corn can be stored to the fullest natural flavor.
The organic yellow glutinous corn there: the skin is thin, soft and glutinous, fragrant, elastic and drawn, full and naturally sweet;
Organic black waxy corn: black and bright color, thin skin, tender and chewy, containing anthocyanins and other amino acids, the nutritional value far exceeds that of ordinary corn.
Organic White Waxy Corn: Nutritious staple food, organic white waxy corn, sweet but not greasy, pure and natural taste.
February** Dynamic Incentive Program
Data ** from Chinese Academy of Sciences).