Study on improving the cropping systems on some main soil types in Dong Hy District - Thai Nguyen Province

<p> 1. The evaluation results of current agricultural cropping system in Dong Hy district showed that: - On one cropland, annual crops were mainly plantedsuch as rice in summer crops, corn, and beans in spring crops. The varieties were mainly local and pure ones with low productivities, the cultivation areas in spring crops were not fully utilized; some soil chemical indicators were suitable for the growth and development of plants. - On two-crop-land: crop structure was 2 – 3 crops/year; plants had the largest areas was rice, including spring rice, early summer rice, main summer season rice and late summer rice with popular varieties such as Khang dan and Bao Thai; corn were planted in the third crop (winter season) on the areas of early summer rice; the areas of main summer season rice and late summer rice still have not been utilized for planting the third crop (winter crops) – there is a possibility to study and select suitable plants for increasing crops; the nutrient content in soil in areas of planting 3 crops/year higher than those in 2 crops/year- this was one of the basis to study on increasing crops to enhance and protect soil fertility. - The agricultural plants in hilly land were mainly tea and some fruit trees, in which the tea cultivation areas had an increasing trend over the years. It indicated the better adaptability and economic efficiency of tea crops than the other fruit trees in Dong Hy. This was also a basis for seeking for measures to improve the efficiency in tea the production in Dong Hy in the future. 2. Research on varieties on fields had some resultsas below: - On one-crop-land, we had studied on selecting some short-term industrial plants, including L14 peanut variety in spring crops that had an average yield of 4.24 tons/ha replacing for Do Bac Giang peanut variety; 23 the DT96 soybean variety in spring crops – had an average yield of 3.13 tons/ha replacing for DT 84 and Cuc Luc Ngan soybean varieties. - On two-crop-land we had some results as below: + two rice varieties , namely LVN20 and HYT100 were selected. These had an average yield from 7.17 tons / ha – 7.70 tons/ ha in spring crops and reached 6.86 tons/ ha – 7.29 tons/ ha in summer crops. These varieties are therefore qualified enough to replaceKhang Dan rice variety, the popular variety with an average yield from 4.7 to 4.9 tons/ ha. + Selected corn varieties were SC164 and LVN99 in winter crops with the average yields of 6.96 tons/ ha – 7.64 tons/ ha, to replace LVN4 maize variety, a popular variety in Dong Hy with an average productivity of 5.32 tons/ ha . + The successfully researched and tested new plants were potato in winter season on two-crop-land in low-level land. The variety had highest productivity was Diamant with an average productivity of 14.66 tons/ha. </p>