Lesson 31. Different Cropping Systems - II

31.1   OVERLAPPING SYSTEM OF CROPPING

In this system the crop is harvested in phases and the vacated area is sown by next crop viz. in case of forage sorghum, part of the crop is harvested for feeding to the cattle or selling out in the market and vacated area is sown with berseem or lucerne. Thus harvesting of sorghum and sowing of berseem is done simultaneously in part of the field in phases rather than sowing entire field in succession. This helps in a continuous supply of green fodder to the cattle as by the time last portion of sorghum field is free for berseem sowing the berseem crop sown in the first place becomes ready for first cutting e.g. Sorghum-berseem/ lucerne.

 31.2   INTER CROPPING

This is a process of growing subsidiary crops between two widely spaced rows of main crop. The main object of this type of cropping is to utilize the space left between two rows of main crop and to produce more grain per unit area.

31.2.1 Principles of inter cropping

  1. The crops grown in association should have complementary effects rather competitive effects.
  2. The subsidiary crop should be of shorter duration and of faster growing habits to utilize the early slow growing period of main crop and they must be harvested when main crop starts growing viz. faster sesamum, sawan, urd or mung grown with red gram complete their life cycle by September, the period since when red gram picks up branching and attains rapid growth. Autumn planted sugarcane remains dormant after germination uptil February during which potato, berseem, lucerne, mustard, etc. could be taken successfully as companion intercrops.
  3. The component crops should have similar agronomic practices.
  4. Erect growing crops should be intercropped with cover crops like pulses so that the soil erosion and weed population could be reduced or checked. This also helps in reducing evaporation loss of water from soil surface.
  5. The component crops should have different root depths so that they do not compete for nutrients, water and root respiration among them.
  6. A standard plant population of main crop should be maintained whereas that of subsidiary crops the plant population could be increased or decreased as per demand of the situation.
  7. Component crops of similar pest and disease pathogens and parasite infestations should not be chosen.
  8. The planting method and management should be simple, less time taking, less cumbersome, economical and profitable so that it may have wider adoptability.

Example: Maize intercropped with green gram, black gram or groundnut etc.

The intercrops differ from mixed crops in the following ways:

 31.2.2 Difference between Intercrops and Mixed crops

                      Intercropping

                     Mixed cropping
  1. The main object is to utilize the space left between two rows of main crop especially during early growth period of main crop.
  2. More emphasis is given to the main crop and the subsidiary crops are not grown at the cost of the main crop. Thus there is no competition between main and subsidiary crops.
  3. Subsidiary crops are of short duration and they are harvested much earlier than the main crop.
  4. Both the crops are sown in rows. The sowing time may be the same or the main crop is sown earlier than the subsidiary crops.
  1. The main object is to get at least one crop under any climatic hazard e.g. flood, drought or frost conditions.
  2. Here all crops are given equal and there is no main or subsidiary crop. Almost all the crops compete with one another.
  3. The crops are almost of the same duration.
  4. The crops may be broadcasted or sown in rows but the sowing time for all the crops is the same.

 Intercropping may be divided in following four groups:

1. Parallel cropping

Under this cropping two crops are selected which have different growth habits and have a zero competition between each other and both of them express their full yield potential.

Example: Mung or urd with maize and urd, mung or soybean with cotton.

2. Companion cropping

In companion cropping the yield of one crop is not affected by the other. In other words, the yield of both the crops is equal to their pure crop. Thus the standard plant populations of both crops are maintained.

Example: Mustard, wheat, potato, etc. with sugarcane

 3. Multi-storeyed cropping

Growing plants of different heights in the same field at the same time is termed as multi-storeyed cropping. It is mostly practiced in orchards and plantation crops for maximum use of solar energy even under normal planting density.

Example: Eucalyptus, papaya, and berseem grown together.

Sometimes it is practiced under field crops such as sugarcane and potato and onion (seed crop) or sugarcane, mustard and potato.

4. Synergistic cropping

Here the yields of both crops, grown together are found to be higher than the yields of their pure crops on unit area basis.

Example: Sugarcane and potato

31.2.3 Advantages of inter-cropping

  1. It offers similar benefits to that from rotational cropping. The nutrients from different layers of the soil are evenly used. A cereal-legume mixture is beneficial because of an efficient fixation of atmospheric nitrogen into the soil. Leaf shedding and their subsequent decomposition reduces the chances of micro-nutrient deficiency in shallow or surface rooted crops like cereals as the legumes absorb such nutrients from lower layer and return them to the surface soil through shedding of leaves and decomposition.
  2. Total bio-mass production/unit area/period of time is increased because of the fullest use of land as the inter-row space will be utilized which otherwise would have been used for weed growth. The farmer gets all his required agricultural commodities from a limited space. Thus the profit/unit area becomes high.
  3. The fodder value in terms of quantity and quality becomes higher when a non-legume is intercropped with legume viz. Napier+cowpea-Napier+berseem.
  4. It provides crop yields in installments which reduces the marketing risks.
  5. It offers best employment and utilization of labour, machine and power throughout year.

31.3 Assessment of land use and productivity in high intensity cropping programme

High intensity cropping needs application of very high input levels and a slight mistake may lead to severe losses. It is, therefore, essential to assess the land use pattern and productivity under such cropping systems. These things may be assessed by using following equations:

1.  Multiple cropping index (MCI). It measures the sum of areas under various crops raised in a single year divided by net area available for that cropping pattern multiplied by 100. It is calculated for each cropping pattern separately and is very similar to cropping intensity :

2. Diversity Index (DD). It indicates the multiply of crops or farm products which are planted in a single year by computing the reciprocal of sum of squares of the share of gross revenue received from each individual farm enterprise in a single year. It may be calculated by using following equation

3.  Harvest Diversity Index (HDI). It is calculated by using the DI equation except that the value of each farm enterprise is replaced by the value of each harvest.

4.  Simultaneous cropping index (SCI). It is calculated by multiplying the HDI with 10,000 and dividing by MCI as stated below:

 5.  Cultivated land utilization index (CLUI). It may be calculated by adding the products of land area planted to each crop, multiplied by the actual duration of that crop to reach physiological maturity and dividing by the total cultivated land area times 365 days:

It is applicable only in sequential cropping and the utility or sanctity of CLUI becomes very limited if the harvesting is delayed or in case of relay cropping and overlapping systems.

 6. Cropping intensity index (CII). It determines the actual land use in area and time relationships for each crop or group as against the total available land area and time. It may be calculated by using following equation:

7.  Specific crop intensity index (SCII). It may be calculated by using CII equation and determines the amount of area-time denoted to each crop or group of crops as against the total time available to the farmer.

8.  Relative cropping intensity index (RCII). It is again a modification of CII which determines the amount of area-time alloated to one crop or group of crops as compared to the area-time actually needed in production of all the crops:

If RCII is more than 50% for a specific crop then that farmer is said to be specialized grower of that particular crop.

 Table 31.1 State wise irrigated area (in %) and average cropping intensity in the 0.5 to 1.0 ha.

State

Net irrigated area

Cropping intensity (%)

Andhra Pradesh

47.6

116.1

Assam

7.2

119.5

Bihar

25.9

133.6

Karnataka

20.9

106.8

Kerala

14.0

116.4

M.P.

14.5

123.4

Maharashtra

13.2

124.2

Orissa

19.6

141.5

Rajasthan

23.0

126.5

T.N.

43.6

122.6

U.P.

42.5

137.9

W. Bengal

17.5

127.6

All India

30.8

128.2

 Source: Indian Agric. 15th edition, directorate of Eco. & Statistics, Min. of Agric. & Irrigation September 1980.

Last modified: Tuesday, 13 August 2013, 4:58 AM