Resolutely relax the small row spacing of cotton-- the second suggestion of consultation service in rural areas in 2008

Before sowing, the author visited some cotton areas in Hebei, Shandong, Shanxi and Shaanxi and found that the small row spacing of cotton in most areas was too narrow, which seriously hindered the normal growth and development of cotton plants, so planting reform must be carried out from the population structure. The top priority is to relax the small line spacing.

In order to cover cotton with plastic film, cotton farmers mostly use large and small rows to sow seeds, one sowing two rows. In most areas, 90 cm wide plastic film is used, and the width of small line spacing is about 45 cm. This is not conducive to the normal elongation of fruit branches and flowering bolls, but also the formation of unbalanced growth on both sides of cotton roots. Many cotton farmers have the experience that when picking flowers, one side of the large row is much more than the other side of the small row.

In recent years, cotton farmers in some areas have used plastic film mulching cotton with a width of 1 meter, which can relax the small row spacing to about 55 cm, which is not only beneficial to the growth and development of fruit branches and roots on both sides of cotton plants, but also can carry out 1-2 times of mid-ploughing between small rows after the film is uncovered in mid-June. it is beneficial to soil ventilation and soil moisture conservation and cotton root growth.

Not long ago, during the rural service in Ruicheng County, Shanxi Province, the author learned that local cotton planting generally uses 80 cm wide plastic film to cover cotton, and the small row spacing is only about 35 cm. This will not only result in uneven growth and development on both sides of cotton plants, but also seal ridges prematurely between rows. If the density is too high and leaf branches are not removed, it will cause a large number of buds and bolls to fall off and the "catastrophic" consequences of less bolls. According to cotton farmers in the southwest village of Dongyi Township, Ruicheng County, the cotton they planted on the Yellow River beach in 2007 yielded only 250,000 and 300 jin per mu, which is directly related to the narrow row spacing, high density and non-removal of leaf branches. There was a cotton farmer who had too few seeds in one eye when sowing, resulting in only one row of seedlings in the two rows and a lot of lack of seedlings in the other row, but in the end he had a yield of more than 400 jin per mu, which was higher in the local Yellow River tidal flat. So to switch to 1 meter wide plastic film, resolutely relax the small line spacing to more than 50 centimeters. If Ruicheng County does not relax the planting reform of small row spacing, it will be difficult to improve cotton yield.

Whether or not to adopt the planting method of equal row spacing can not be generalized, but depends on soil fertility, watering conditions and the potential of varieties to increase yield. In the case of no guarantee of watering and low soil fertility, it is not suitable to plant with equal row spacing, let alone blindly adopt a wide row spacing of 1 meter. Because the equal row spacing of 1 meter is difficult to guarantee the density of more than 2000 plants / mu, it is easy to cause low leaf area coefficient and large gap between rows in case of drought, which can not make full use of land and light, gas and heat resources. For general soil fertility, irrigation conditions and conventional varieties, under the condition of full chemical control, it is appropriate to have equal row spacing of 80 cm, plant spacing of 1 foot and 2500 plants per mu in the northern cotton area. If the row spacing is further reduced, it will bring difficulties to sowing and film mulching, so it is more convenient to use large and small rows to plant.