Có 26+ tài liệu thuộc chủ đề "kĩ thuật canh tác"
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Những công việc có thể gây bệnh là tất cả mọi công việc có tiếp xúc với bụi silic tự do như:. Sản xuất và sử dụng các loại đá mài, bột đánh bóng và các sản phẩm khác có chứa silic tự do.. Công việc đúc có tiếp xúc với bụi cát (khuôn mẫu, làm sạch vật đúc. Khi...
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Water harvesting and soil moisture retention. Antoinette Kome, Rob de Neef and Ton van de Ven have filled the gap by writing this Agrodok: 'Water harvesting and soil moisture retention'. The water harvest- ing techniques described are particularly useful in arid and semi-arid areas, but the techniques described for soil moisture conservation are also of use in sub-humid regions.. Agromisa...
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3 Designing water harvesting systems. When designing a water harvest- ing system the size of the catchment area is calculated or estimated, in order to ensure that enough runoff water is harvested for the crops in the cultivated area. For seasonal crops a C:CA ratio of 3:1 is often used as a rule of thumb: the catchment area C is...
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Silt trapped on the higher side of the barrier forms natural terraces (Figure 10).. Where there a few stones available, stone lines can be used to form the framework of the system. The soil is carried away by runoff (and tillage) from the lower side of the upper line (Figure 10 (b)) and deposited at the higher side of the...
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In this second part soil moisture retention techniques to be applied in the cultivated area are described. The objective of contour farming is to increase infiltration into the soil along the contours and to conserve soil moisture there. One method for marking out contour lines, the water tube-level, is de- scribed in Appendix 3. All subsequent water conservation measures are...
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Reducing evaporation losses and optimizing the use of soil moisture 77. 9 Reducing evaporation losses and optimizing the use of soil. Windbreaks can be non-living structures such as brushwood and woven palm-frond fences or living hedges such as lines of shrubs, trees or tall grasses. In areas prone to wind they give shelter to crops and reduce evaporation of soil...