抄録
The survey of customary farm practices for improving the cropping system in Guyan Prefecture of Ningxia Autonomous Region, which is located at the western part of the Loess Plateau in China, was carried out. This work has been conducted as a part of the research project on the “Fundamental study of the establishment of grasses and crops on the Loess Plateau in China” sponsored by the Ministry of Education, Science and Culture, Japan. In this paper, we described the farm practices of flax, millet and pea, of which there were consisted crop rotation. We have already reported in our previous paper about wheat, which is one of the rotation crops.
1) Flax is an important oil crop in this area. however, farmers have made little effort to improve its cultvation because increasing the yields of food crops like wheat has been considered more important. In the cultivation of flax, farmers plowed their fields three times in autumn, this was the same as in the case of wheat cultivation, but generally they did not apply any organic fertilizer at that time. In spring, after finishing stirring tillage for weeding, farmers sowed the seeds with the same seeder as that for wheat sowing. During the growing season, farmers weeded only once with a hoe. For the harvest system, farmers pulled out the plants, bound them, and then shocked them in the fields. After drying plants, farmers piled them up and then threshed them whth a stone-made roller. The labor requirements for the flax cultivation was 43.5-50.5hr/10a, which was the lowest value among all the rotation crops. The reason for the low labor hours was that farmers did not have to carry and spread any organic fertilizer for this crop.
2) Proso millet and foxtail millet have been cultvated in this area for many years. In recent years, however, the planted areas of those crops have been gradually decreasing because of an increase in wheat production. The method of land preparation in autumn for proso millet was the same for flax. In spring, farmers sowed the seeds with a seeder 10 to 15 days after spreaping organic fertilizer and plowing. In the process of crop rearing, farmers gave trampling with a roller to the young plants and weeded by hand. The harvest system for proso millet was almost similar to that of wheat. However, the plants were not piled up because the proso millet would not dry easily. The labor requirements for proso millet cultvation was 51.5-58.5hr/10a, whch was smaller than that for wheat cultivation.
3) Pea is mainly cultivated for keeping soil fertility high. Farmers cropped with pea in the fields after having harvested millet in late-September. Because the suitable period for autumn land preparation for pea was very short, farmers could plow the fields only once. In following spring, farmers plowed the fields, sowed the seeds by hand, spread organic fertilizer, and covered the seeds with turned soil of the next furrow, as a series of farm practice. During the growing geason, farmers weeded only once. The harvest system of pea was very similar to that of wheat. The labor requirements for pea cultivation was 49.0-59.8hr/10a, which was nearly equal to that for proso millet.
