Cropping Patterns and Crop Protection Management | Science Class 9 PDF Download

Cropping patterns :- Different ways of growing crops can be used to give maximum benefit.
 They are models of raising crops which help in obtaining maximum benefit from the same piece of land, reduce risk of crop failure, disease and infestation. Three common types of cropping patterns are mixed cropping, intercropping and crop rotation.

Mixed Cropping
 Mixed cropping is the technique of growing two or more different crops together in the same field.
 The technique is an insurance against crop failure due to adverse weather and attack of pathogens and pests.The different crops to be grown together are so chosen that they do not have common pests and pathogens or similar requirements of water and minerals. Rather the products and waste materials from one crop stimulate the growth of the other crop.Eg. _ Groundnut and sunflower/gram, ragi and gram, wheat and gram/mustard.

Criteria for Selection of the Crops
 The following criteria are taken into consideration while selecting crops for mixed cropping :

(i) Root Pattern :- Both the crops should not have same root pattern. One crop should have deep penetrating roots (e.g., dicot) whereas other should have shallow roots (e.g., monocot).

(ii) Water Requirement :- Both the crop plants should have different water requirements. If one of the crops requires higher amount of water, the other should require lesser amount.

(iii) Nutrient Demand :- If one of the crop plant requires higher amount of nutrition, the other should require lesser amount of nutrition.

(iv) Duration of Crops :- Both the crops should have different maturation time. If one is long duration crop, the other should be of short duration (early maturing).

(v) Growth Habit :- If one plant is tall, the other should be dwarf. They should have different structure of leaves, stems, branching pattern of stem and flowers (different canopy).

Advantages of mixed cropping

1. No risk of complete crop failure.

2. Increase in Yield :- When cereal or non-leguminous crop is grown alongwith a leguminous crop, the deficiency of nitrogen in the soil, caused by the growing cereal crop, is compensated by the enrichment of the soil in nitrogen compounds by the growing of leguminous plants. So, it increases the yield.

3. Variety of Produce :- We can harvest variety of produce like pulses, cereals, vegetables or fodder.

4. Improvement in Soil Fertility :- Growth of leguminous crops improves soil fertility and reduces the requirement of fertilizers.

5. Reduced Pest Infestation :- The chances of pest infestation are reduced because the pest of one crop rarely finds the same plant nearby 

Disadvantages of mixed cropping :-

Farmer faces difficulty in applying fertilizer to individual crops. Farmer faces difficulty in spraying pesticides on individual crops.

Harvesting and threshing of crops separately is not easy, because seeds of the two crops are mixed and then sown (there is no set pattern of rows of crops). 

Do you know ?
Mixed Farming :- It is raising of different types of crops (food grains, fibres, oil seeds, vegetables, etc.) and animals (cattle, fish, poultry, apiary) on the same farm. It ensures good returns to the farmers and provides for easy availability of various articles. 

INTER-CROPPING 
Intercropping is growing two or more crops simultaneously in different strips or rows in a same field in definite row pattern. Row patterns like 1 : 1, 1 : 2 or 1 : 3 can be followed. The crops selected for Intercropping have different nutrient requirements, different sowing and harvesting dates.
 e.g., Soyabean Maize, Finger Millet (bajra) Cow Pea (lobia).

Advantages of Intercropping :

1. Productivity :- Intercropping increases productivity per unit area.
2. Sowing :- Seeds of different crops can be sown separately.
3. No mixing :- There is no mixing of crops.
4. Fertilizers :- Specific fertilizers required for each crop can be added.
5. Pesticides :- Pesticide and weedicide required for each crop can be applied.
6. Harvesting :- Each crop can be harvested, threshed and marketed separately.

Differences Between Mixed Cropping and Intercropping 

CROP ROTATION
 Growing different crops on the same piece of land in a pre-planned succession is called crop rotation. Generally a leguminous crop is rotated with non-leguminous crop.In this way, rotating different crops (e.g., leguminous and non-leguminous crops) in the same field replenishes the soil naturally and leads to increase in the crop production.

Depending upon the duration, crop rotation is classified as

Advantages of Crop Rotation

1. Attack by insects and fungi is minimized because different pests are associated with different crops. By varying the crops, the insects and fungi associated with the crop usually disappear.
2. Rotation of crops helps in weed control :- This is because weeds are associated with specific crops. When the crop is changed, the weeds associated with the crop usually disappear.
3. Rotation of crops improves the fertility of the soil and hence brings about an increase in the production of food grains.
4. It saves a lot of nitrogenous fertilizer, because growing leguminous crop, during the rotation fixes atmospheric nitrogen with the help of their nitrogen fixing bacteria and there is no need to add nitrogenous fertilizer to the soil.
5. The chemical nature of the soil is not altered as different crops require different types of fertilizers.
6. The land is not kept free of cultivation :- Two to four crops are raised which increases the income of farmers.

3. Crop protection management 
In fields, crops have to be protected from weeds, insects-pests and disease-causing organisms like fungi. All these cause damage to crop plants so much that most of the crop is lost. Thus, crops can be protected by the following methods :
 Use of pesticides.
 Use of resistant varieties.
 Crop rotation and other cropping systems 
 Summer ploughing.  
Pest :-
 Any destructive organism that causes great economic damage or destroying crop plants are called pests. 
 Examples : Weeds, insects, mites, nematodes.

Pesticide / Biocide :-  It refers to a chemical that is used to kill a pest organism which includes insecticides (for killing the insects),weedicides (for killing the weeds), fungicides(for killing the fungi) nematicides (for killing nematodes) and rodenticides (for killing rodents).   

Advantages of pesticides : They kill pest quickly, increase food production and are easy to store. 

Disadvantages of using pesticides :

• They cause soil and water pollution.
• Residue left on the fruits & seeds is harmful for human consumption.
• They destroy even the useful insects. 

Preventive measures avoiding use of pesticides : Crop rotation, multiple cropping and field fallow.

Sowing healthy seeds and summer ploughing. 

Use of pest and disease resistant hybrid varieties of crop plant.

Field also need to be protected by grazing animals by raising wire fences and boundary wall. 

Birds are scared away by raising scarecrows and beating of drums.

Weed :- 
 They are the small-sized unwanted plants which grow along with a cultivated crop in a field. Weeds are economically very important as they can severely reduce crop yields by competing for light, water and nutrients.

Some common weeds :- Xanthium (Gokhroo), Parthenium (Gajar grass),Convolvulus, Cyprinus rotundus (Motha), Amaranthus (Chaulai), Chenopodium(bathua).

Method of weed control :- 

Mechanical method :- Uprooting, ploughing, burning and flooding,

Biological method :- Use of insects or some organisms which consume and destroy the weed plants.

e.g. Prickly-pear cactus (Opuntia) is controlled by Cochineal insect and aquatic weeds (Hydrilla) are controlled by Carps fish.

Chemical control :- Spraying of chemicals like herbicides or weedicides.

e.g. Isoproturon, 2,4-D, MCPA, Atrazine.

Crop disease :-  When the pathogens such as bacteria, fungi and viruses get favourable conditions for growth and propagation, they spread and infect the crop plants causing crop diseases. Depending upon their mode of occurrence.

Crop disease are of following type :-

Seed borne :- Spread through the seed. Example :- Ergot of bajra and leaf spot of paddy.

Soil borne :- Spread through the soil. Example :- Smut of bajra and Tikka of ground nut.

Air borne :- Spread through the air. Example :- Rust of wheat.

Storage :- Proper storage is necessary to get seasonal food regularly throughout the year. Freshly harvested grains have more moisture. If freshly harvested grains are stored without drying, then they may get spoil and lost their germination capacity. Hence before storing them the following precautions must be undertaken.
Precautions :

• Grains should be safe from moisture, insects, rats, and microorganisms.
• Grains must be properly dried in the sun to reduce the moisture in it.
• Grains must be stored in jute bags or metallic bins.
• Store grains in silos, granaries and godown with chemical treatment to protect them from pests.
• Dried neem leaves can be used for storing food grains at home.

 Factors affecting stored food : 

(i) Biotic factors : e.g. insects, micro-organisms, mites, birds, rodents and other animals.

 (ii) Abiotic factors : e.g.moisture, humidity and temperature.

Food materials can be broadly classified in to two types _

1. Perishable food materials :- They get spoiled easily on keeping for some time at room temperature.

Example :- Fruits, Vegetables, meat, milk etc.

2. Non perishable food materials :- They do not get spoile for long time at room temperature. 

Example :- Wheat, Maize, Pulses, Rice.) 
 Non perishable food materials are stored on a commercial scale in gunny bags or in grain silos.

Pesticides are applied on the stored food grains either by spraying or by fumigants.

(i) Spraying :- Malathion and pyrethrum are commonly used by spraying.

(ii) Fumigantes :- Volatile pesticide are called fumigants.

Ethylene dibromide (EDB), aluminium phosphide.

Celphos, CH₃Br, Zinc phosphide.
DO YOU KNOW?

Buffer stock : Surplus stock of grains which is preserved for emergencies like drought and floods is called buffer stock.

Food grains are stored in large godowns by agencies like Food Corporation of India (FCI) and state warehousing corporations.

Fruits and vegetables which have high water content are stored at 0°C to 1°C temperature.

Drying, canning and freezing are some of the methods of crop preservation.

Drying reduces the moisture content, canning prevents the microbial growth and freezing reduces the rate of respiration of microbes.