1. Principles and concepts of cropping systems

Transcript

Hi Friends, in the last lectures we understood about the overview of rainfed agriculture in India. So in these lectures let us study about the principles and concepts of cropping systems. Before actually going to the actual topic, we need to learn about two definitions with this subject. First one is cropping system. The cropping system means cropping patterns practiced on a farm. There may be so many cropping patterns that are being followed in a farm. So whatever the cropping patterns followed in this are called by the name ‘cropping system’. Then what are the cropping patterns. The cropping patterns are different crop sequences. So this is a one which is related to crop sequences followed in a year. So cropping system means the cropping patterns followed in a year. Then the cropping patterns, which is different crop sequences followed in a year. These two terminologies we have to understood.

Next coming to the factor. In case of drylands, rainfall is the main and most variable source of water for dryland crops. As you already know, in rainfed drylands, the source of moisture is rainfall. So it is one and only source of moisture in case of rainfed drylands. The second one is. Rainfall variability plays a dominant role in influence the crop growth and yield in crop planning. Coming to the factor understanding,

• the source of moisture that is rainfall
• next comes the factor, rainfall variability.

So rainfall variability is a chief factor which is helpful in deciding the; what are the cropping plants, what are the cropping plants that should be adopted in a farm. That means it helps in the crop planning. Then the third one is. Cropping pattern is in a region is usually planned on the basis of prevailing rainfall behavior. The cropping pattern of one region differs from the other region in every states. Why this is so? This is so because, each region is having its own rainfall behavior.

• The amount,
• the soil,
• the topographical factors.

So considering all these factors. And also involving rainfall as one of the factors. The particular region’s crop plan will be derived. So while devising cropping pattern of a region is planned on the basis of prevailing rainfall behavior in that region.

Coming to the important climatological inputs in the crop planning. So what are all the climatological inputs that have to be taken into consideration for the crop planning.

• One is seasonal rainfall. So seasonal rainfall, it infers what is the amount of rainfall, that is the amount of rainfall. That is, in a region during the season. This is being done over the years by calculating the mean of the average rainfall for a particular region for a particular cropping season, say for example kharif season. What is the seasonal rainfall? So this is also taken into consideration for the crop planning.
• Then the second one is probable period of assured rainfall distribution. After taking into the factor, seasonal rainfall. So what is the probable assured distribution time in this region. So seasonal rainfall, whatever the amount of rainfall that is due to occur; at what time it’s distribution is likely to. So this is also taken into one of the climatological factor for the crop planning.
• Then the third one is long range forecast and the medium range forecast. You are already aware that the Indian Meteorological Dept is providing time to time, the long range forecast and also the medium range forecast. So these two will also be taken into consideration for the crop planning.

So important climatological inputs into the crop planning of seasonal rainfall, probable period of assured rainfall, long range as well as medium range forecasting. Coming to the after understanding the rainfall factors or the climatological factors. We have to understand, what type of crops have to be selected for cultivation under dryland situations. So not all the crops are being able to cultivate in drylands. There are some characteristics which have look into the each crop species. So let us see, what are the characteristics of the crops. And also in the crops, what are the characteristics of the varieties, that are suitable for drylands.

So before going to the characteristics, the one and the only characteristics which we have to decide is; capacity to produce a fairly good yield under limited moisture conditions. As you all know, the drylands there is a limited moisture conditions. So whatever the crops or the varieties selected, they should have a capacity to produce good yield under soil limited moisture conditions. This is one of the important criteria one has to looked into. Let us see what are the other characteristics of the crops or the varieties, which we have to decide for the drylands.

• The short life cycle or the yearly reproductive cycle. The crop or the variety which is selected should have a very short life cycle or the reproductive life cycle. Why it is so? Has understood in these drylands, the period of moisture availability is very less. So the long duration crops cannot be grown under dryland conditions. So the whatever the crops or the varieties selected should have a shorter life cycle. Only such of the crops will do or will perform well under the dryland situations.
• The second one is photo insensitive. This is something which is concerned with the photo-periodic characters. Photo insensitive is that, that particular crop or the variety can be grown in any season of the year. That means photo insensitive. It is not photo sensitive. Photo sensitive means the particular crop has to be grown during that season only. So here we have to select a crop which is photo insensitive. That means it can be grown in any season of the year. Such of the crop should be selected
• Then the third one is strong and penetrating root system. The crops are the varieties which have been selected should have a strong and penetrating root system. This is because of the fact that if the crop or the varieties have this strong and penetrating root system, they can extract the moisture from the deeper layers of the soil, so as to support the plant growth in a better way under limited moisture conditions.
• The fourth one is low water requirement. As you all know each and every crop has its own water requirements. It may be high, it may be low, so anything else it has its own water requirements. So for the crops which are to be selected for the dryland situation, should have a low water requirements. Because of the fact that in drylands, we have a limited moisture conditions, and water will not be; high amount of water will not be available for the crop growth. So in that sense, the crop or the varieties selected should have a low water requirement.
• Then higher harvest index. The harvest index is nothing but the economical over the biological need. So the crops which have been selected in the dryland situation should have a higher harvest index.

So these are the characteristics or these are the points should be kept in mind, while selecting a crop or a variety for the dryland situations. After knowing the what type of crop has to be selected. Let us go for the types of cropping systems. Which type of cropping systems we have to adopt. Whether it is a monocropping, whether it is a inter-cropping, whether it is a multiple-cropping. So types of cropping systems, that is under that.

• First is mono-cropping. In that a single crop is grown on a piece of land. The same crop is grown every year. In case of drylands, the mono-cropping is also practiced, wherein a single crop is grown year after year on the same piece of land. Take for example groundnut. The groundnut is grown year after year on the same piece of land. So this type of cropping system is called as monocropping. In this there is no diversity in the crop species. Only one crop is grown. Then predominant crops in drylands are, groundnut, sorghum, finger millet. These are the predominant mono-crops in drylands; that are groundnut, sorghum and finger millet.
• Then coming to the next set of cropping systems, that is multiple cropping system. In case of multiple cropping system, two or more crops are grown on the same piece of land in one calendar year. Multiple as the name itself indicates. Two or more crops are grown on the same piece of land in a one year. So this is called multiple-cropping systems.

I will stop this lecture at this point. And this lecture will be continued in the next class.

Thank You.