Erosion control in the tropics - Part 4 docx

... Erosion control in the tropics 28 Removing this soil from the drainage system or the paths adds to the workload of the farmer. ? The reverse applies of course to the field where the soil ... labour and the farmer is obliged to sow up a smaller area for in- stance. ? When thin layers of soil are continually washed away from the field by erosion, the bigg...

Ngày tải lên: 02/07/2014, 05:20

... clear that when observing the erosion phenom- ena, the important thing is always to trace the causes of it. In the fol- lowing chapters we will go more deeply into the erosion process, which ... keep the course of the erosion process in mind when looking for signs of erosion in the field. When a certain characteristic is no- ticed, one should ask oneself just w...

Ngày tải lên: 02/07/2014, 05:20

... ? Taking the sow away from the piglets during weaning, rather than removing the piglets. ? Putting the sow in a pen next to the boar after weaning. ? Bringing her into contact with the boar ... heat within 14 days of weaning, there are various possible causes: ? The suckling period has been too long - the shorter the period, the quicker she will come on heat...

Ngày tải lên: 01/07/2014, 19:20

... growing in the tropics 40 4. 3 Concluding remarks Most fruit crops can be cloned in different ways. Budding and grafting are only used where cuttings or layers do not root, or where the root- stock ... remain smaller and can be planted close together. More trees per ha means further increases in the early crops! Taking the cuttings from a high-yielding mother tree also c...

Ngày tải lên: 02/07/2014, 00:20

... an insight into the causes and the course of the erosion process, by stating the factors which influence the mechanism of erosion and how these factors are linked up. Introduction 9 If the ... erosion here. There are really two types of erosion, natural and accelerated erosion, also called man-made ero- sion. ? Natural erosion is going on all the time; the weat...

Ngày tải lên: 02/07/2014, 05:20

... Erosion control in the tropics 20 Organic matter content of the soil Organic matter probably is the most important factor in binding the soil particles. The better the soil particles ... of erosion is likely to occur. 3.1 Splash -erosion and stream -erosion Within water -erosion there are two types of erosion: splash erosion and stream erosion. Certainly...

Ngày tải lên: 02/07/2014, 05:20

... and at retaining the rain water. ? Minimum tillage, mulching and the use of a cover crops serve to protect the soil against the force of the rainfall, at the same time maintaining the soil fertility ... guideline for the width of strips Slope of Width of 0 - 2% 40 - 50 m 2 - 4% 30 - 40 m > 4% 15 - 30 m in very humid areas 15 - 30 m This...

Ngày tải lên: 02/07/2014, 05:20

... again. Burning is an integral part of cattle farming in the tropics and improvements in the technique must be found. The timing and the method of burning seem to determine whether it is damaging ... drinking places and in doing so they trample down the soil. During rain showers water collects in the trampled tracks (the rain does not necessarily affect the str...

Ngày tải lên: 02/07/2014, 05:20

... drain The main drainage serves as the main channel where all the water is collected. ? One main drain at the bottom of the catchment area: all the col- lected water ends up in the main drain ... Strengthening of a gully Checkpoints for making dams When laying out these check dams, the following points should be taken into account: ? The principle is to shorten the...

Ngày tải lên: 02/07/2014, 05:20

... yourself why erosion occurs in a certain area. Not only will the deeper causes of erosion be found in the socio-economic backgrounds, but the incentive will be found which motivates the farmer ... Underlying causes of erosion 73 8 Underlying causes of erosion In the previous chapters we have seen how the chance of erosion can be lessened by taking certain prec...

Ngày tải lên: 02/07/2014, 05:20