Đang chuẩn bị liên kết để tải về tài liệu:
Cultivation of soya and other legumes - Part 2

3 Cultivation requirements for legumes This chapter is about how to grow soya and other legume crops. To grow legumes successfully farmers need to know about the following: ? climate requirements ? soil type and soil fertility requirements ? when to sow ? suitable varieties ? how to combine legume crops with other activities on the farm | 3 Cultivation requirements for legumes This chapter is about how to grow soya and other legume crops. To grow legumes successfully farmers need to know about the following climate requirements soil type and soil fertility requirements when to sow suitable varieties how to combine legume crops with other activities on the farm Practical examples show how legumes can be integrated into local farming systems and under which conditions legumes grow well in different areas of the world. 3.1 Suitable areas Legumes and soya can be grown under a wide range of agroclimatic conditions. We list the main ones here to give the reader an idea of the variety of conditions under which legumes do well. Upland river terraces and hills where shifting cultivation takes place Shifting cultivation is a system in which farmers cut down an area of trees burn the remaining vegetation and use the land they have cleared for agriculture. The ash from the burned material contains a lot of nutrients so the soil is fertile and in the first season crops with high nutrient requirements can be grown. In the following seasons other crops are grown. In traditional shifting cultivation systems a piece of land was usually used for three or four years after which the soil was exhausted and weeds would start to take over. The land would then be left fallow for a period of 10 to 15 years giving the soil time to recover after which the cycle would start again. This system is now under pressure how 10 Cultivation of soya and other legumes ever as the fallow period becomes shorter and the soil and vegetation have less and less time to regain fertility. In many places land is cultivated after each rainy season weeds become more and more difficult to control and soil fertility is decreasing. The lack of nitrogen in the soil is a big problem. Legumes can help to restore nitrogen deficiencies and stop weeds taking over. For example Mucuna utilis can help to suppress Imperata a stubborn grassy weed which prevents