3. Agronomic measures in dryland agriculture

Transcript

Hi friends, in the last lecture we studied about an overview of soil and moisture conservation measures, as well as the concept of watershed management. In this lecture let us study about the agronomic measures that are being adopted in drylands. Coming to the agronomic measures in drylands. Soil and water conservation, it includes both agronomical as well as mechanical measures. The agronomical methods are supported with mechanical measures, where the land slope exceeds the permissible limits. There to say that, soil and conservation measures. In that we will adopt both agronomical measures as well as mechanical measures. But in certain of the cases, these agronomical measures will be supported by mechanical measures, where the land slope exceeds the permissible limit.

So these basically agronomic methods are used in inter-bunded areas, and mechanical measures compliment to help boost the crop yields in the rainfed drylands. Where will be these agronomical measures usually adopted? These agronomical measures will be mainly adopted in the inter-bunded areas, that is in the croplands. In the croplands, these mechanical measures compliment the agronomical measures in boosting the crop yield from the drylands. Coming to the agronomical measures; in that the contour tillage. All the agricultural operations are to be done in the contour, or across the direction of slope, where the holdings are very small. Contour tillage is the tillage wherein, all the activities, all the agricultural operations. They have to be carried out along the contour bunds. This is called contour tillage.

Even though the operation is very simple, it plays a major role in the process of soil erosion through the runoff. When we do so, when this is done, all the activities are being done on the contour lines. It tends to arrest the soil erosion and it also stores the runoff water and also soil moisture. It also conserves the soil and due to increased time of concentration, more rainwater seeps through the soil profile to recharge the water. What happens in case of contour tillage? The moisture gets more time of concentration to seep into the soil and also after seepage into the soil, it is going to recharge the water. In this way contour tillage is very helpful. As you might have seen in this. The contour, this is the contour. The tillage will be done across this. In this way the contour tillage is being done.

Coming to the second one. The dead furrows. When all the tillage operations are complete, it is advisable to leave a dead furrow at every 10 meter interval. This should remain in the position until the crop is harvested. This is also even the operation is very simple, it plays a major role in retarding the process of soil erosion through runoff. You can see here the dead furrows, wherein at an every 10 meter interval, this dead furrows are being opened, and these dead furrows act as a point of soil moisture storage. So dead furrows aid in reducing the runoff velocity and they also conserve the water. By opening the dead furrows, the velocity of the water can be reduced and it is made to seep into the soil, thus conserving the water.

Then next one is organic matter. Adding organic manures, such as farm yard manure and compost every year as basal application to soil, improves the soil physical conditions. The organic matter improves the activities of soil micro-organisms and also provides the much needed micro plant nutrients of all kinds, besides nitrogen, phosphorous and potash. The adding of organic matter. The organic matter can be added in many ways. It can be in terms of green manures, and they can be incorporated into the soil and you can apply the formal manure also. Application of these organic matter into the soil will increase the activity of the micro-organisms and decomposition of the crop residues, and besides supplying the primary nutrients; nitrogen, phosphorous and potassium along with the plant micro nutrients.

Next coming to the choice of the varieties. There are two types here. We have to adopt drought resistant varieties and also early maturing varieties.

• These drought resistant varieties. Varieties with proven genetic character to withstand longer periods of drought. These varieties perform well in situations where the interval between the rainy days are long. So drought resistant varieties, which the proven genetic character has to be used. So what is the purpose. These varieties, when they are planted in the soil and when the long dry spells occur during a cropping period. They are able to withstand this moisture stress, because of their genetic character of drought resistance. So in drylands drought resistant characters, the varieties with drought resistance have to be used.
• The second category is, early maturing varieties. Varieties with shorter duration life cycle, should be chosen so as to cut down the water requirements of the crop. The success rate of short duration crops is greater than the long duration crops. In case of drylands, the short duration varieties of the crops should be used, so as to lower the water requirements. So these short duration varieties, they complete their life cycle in a very short period. And coupled with this, they have a less water requirements. So that whatever the available little moisture is available, these can be utilized by the short duration varieties. In case of drylands, the success rate, where the short duration varieties or the short duration crops are being used, the success rate is very high, when compared to using longer duration varieties.

So these are some of the agronomical measures that are being used in case of drylands. I will stop this topic at this juncture. And I will continue the same topic in the next lecture.

Thank You.