4. Agronomic measures in dryland agriculture – Contd.

Transcript

Hi friends, welcome back to the lecture. I will be continuing with the previous lecture topic. In the previous lecture we were discussing about the agronomic measures, that are being adopted in drylands. These agronomic measures are being carried out in inter-bunded areas, that is in croplands. In certain of the cases, where the land slope exceeds the permissible limits. In those areas agronomical measures as well as mechanical measures will be put together, they will be used. In the previous lecture we have studied certain of the agronomical measures. And in this lecture, I will be continuing with the same topic, that is agronomic measures.

Coming to the agronomic measures, in that seed rates. So seed rates, every crop will have a recommended seed rates. So if it is a normal season, sowing is done with a normal seed rate. So in that selective thinning is recommended, if the occurrence of drought is expected to reduce the plant population. Use of scarce soil moisture among the fewer plants. So if it is a normal season, the normal seed rate is recommended. But during the crop growth, if the occurrence of the drought is expected. Then the thinning is recommended. Thinning means removal of unwanted plants, thinning of more plants, thinning of extra plants, that is removal of extra plants is recommended. By this the plant population will be cut down, so that whatever the few plants left over, they can use the limited water moisture available. So this is the idea behind carrying out the thinning.

Coming to the late season. If there is a late season, where the monsoon is moderately delayed. Normal cropping with reduced seed rate is advised. If there is late season. If the sowing is carried out beyond the recommended season; beyond the recommended time, that is during the late season, wherein normal cropping practices can be followed, but with a reduced seed rate. Why it is reduced seed rate? Reduced seed rate is because, to have smaller populations of plant, so as to utilize the left-over moisture by the fewer plants. So this is with respect to seed rates. Normal season and delayed season, we have different seed rates.

• Coming to the Line Sowing. This line sowing on contours is essential. It arrests the runoff and conserves the soil being eroded. It helps in the labor efficient implements in weeding. So always line sowing is advisable. In the line sowing because of the definite planting geometry, wherein the plants are planted at equi-distances at pre-described distances, it arrests the runoff, and it will store the soil moisture. And also it is recommended because if the line sowing is taken, the weeding can easily be taken between the spaces of the plant rows. In this way line sowing is advantageous in drylands.
• Coming to the wider spacing. Wider spacing between the rows and between the plants within the row. This reduces the plant population. Competition between the plants for scarce soil moisture. The fewer plants have greater access to limited available moisture. In case of drylands wider spacing should be followed. That is wider spacing between the rows and between the plants. Wider spacing should be followed. Why it is that wider spacing should be followed? Here this reduces the plant population and there will be smaller plant population, which can have access to the limited moisture available in drylands. So in this way line sowing and wider spacing are advisable in case of drylands.
• Coming to the weeding part. The frequent weeding is an important part of the dryland agriculture. Line sowing and mechanical weeding with appropriate size of blade harrows/cycle weeders remove the unwanted vegetation, which competes with the main crop. Absolutely weeding will be carried out. The purpose of carrying out weeding in the drylands is that whatever the extra plants, unwanted plants are there, they compete with the main crop for resources. So when these unwanted plants are removed through cycle weeders or blade hoe. So whatever the moisture available, they can be utilized by the crop plant successfully. So removal of weeds helps the main crop obtain greater accessibility to soil moisture and plant nutrients for its own growth. Otherwise whatever the unwanted plants, or otherwise they are called as weeds. They will rob away the nutrients and the moisture from the soil, and they make these unavailable to crop plants. If they are removed then the crop plants will have an accessibility to these resources easily. In this way weeding is essential agronomic measure in case of drylands.

Strip Cropping

Coming to the strip cropping. Strip cropping is a practice wherein raising erosion permitting crops along with the erosion resistant crops having abundant adventitious root system and providing high percentage of canopy in strips. Here a few rows of erosion permitting crops and followed by a few rows of erosion resisting crops will be planted. This is what we called as strip cropping. What happens in case of strip cropping. These two types of crop plants will have adventitious root system and also they have higher percentage of canopy, which can arrest the loss of moisture. The close growing erosion resisting strips are generally legumes which fix nitrogen in the soil. In this strip cropping generally legumes will be selected, because of the fact that they have nitrogen fixing plants. The increased resistance to the runoff in the erosion resisting crops results in higher volume of water percolating through the soil profile, due to increased time of concentration, and the canopy also protects the soil from the beating action of the soil.

In case of strip cropping, wherein erosion resisting crops resist the soil because of higher concentration of time will be available for the water to seep into the soil. In this way they have arrest the runoff. Then also because of their spreading canopy, they also avoid the beating action of the rain. So in this way strip cropping is highly advantageous in case of drylands. So this is a picture where the strip cropping is grown. This is the erosion permitting crops. So followed by these are the erosion resisting crops. So here the runoff will be arrested, because of the more concentration time available to percolate into the soil, and because of the wider canopy of the legumes, the it saves the soil from the beating action of the rain.

Mixed or Inter-Cropping System

Coming to the mixed or the inter-cropping system. We have already studied in the lecture about the cropping system, wherein the mixed or inter-cropping systems, they are the forms of multiple cropping, wherein these cropping system acts as the insurance against the crop failure. Whenever the main crops fails the component crops will give some sort of income to the farmer. In a way it acts as an insurance against the crop failure. So different root systems of mixed crop feed at different depths of the soil. So the soil moisture will not be taken away from the same depth, because in the mixed cropping systems or in the inter-cropping systems the crops will be selected in such a way that both the crops will have a different rooting pattern. When they have different rooting pattern, they extract the moisture from the different layers. So there not be competition for nutrients. And also in mixed cropping and inter-cropping will fetch fewer grains, very little quantity of grains for the farmer.

So this is the picture where the mixed and inter-cropping can be seen. Groundnut+ pigeon pea in 8:2 ratio, wherein groundnut is grown in 8 rows and pigeon pea is grown in 2 rows. Then in case of finger millet+ pigeon pea, wherein finger millet is grown in 8 rows and pigeon pea is grown in 2 rows with the formation of dead furrow. So this is about the mixed or inter-cropping. It is very useful as an agronomic measure in drylands.

Agri-Horticulture

In the previous lecture we studied about the horticulture components. Agri-horticulture, it is an important alternate land use system, wherein the marginal lands do not produce good annual crop returns, even in the normal seasons. So these kinds of soils are best used for raising trees of economic value and creating permanent assets. We have already understood that always the crop plants are not in a position to produce the desired results. In such a situation tree based components should be adopted. This is one of principles adopted in the alternate land use systems. So in this Agri-Horticulture provides a viable enterprise, wherein agriculture component is grown along with the horticulture component.

So these lands are also good for raising dryland horticulture crops, such as mango, cashew and tamarind. A part of the land could be earmarked specially for planting mixed tree species known in the area for providing fuel, fodder and timber. In case of agri-horticulture system, the farmer can reserve a part of the land for this agri-horticulture activities, so that he will be getting along with the crop component a fruit plant and nutritious security. Next coming to the crops suitable for dryland horticulture. The fruits; mango, sapota, guava, ber, tamarind and custard apple can be selected for the dryland horticulture.

So with this we are concluding the use of agronomic measures in the drylands, with the conclusion that agronomic measures contribute a lot for enhancing production in drylands. However timeliness and preciseness in performing the operations in the field should be taken care of. No doubt these agronomic measures contributes a lot for the dryland production. However the timeliness of the operation and preciseness with which these operations perform will yield a better results in case of drylands. With this I am concluding the topic on agronomic measures. I am also concluding the lecture.

Thank You.