Green Manuring Muhammad Usman

2012-ag-2995

A growing crop, such as clover or grass, that is plowed under the soil to improve fertility

Definition

Nitrogen and phosphorus are deficient in

Pakistani soils and there is hardly any soil from which high yields can be obtained without any fertilization.

Why we do green manuring

The production of high inorganic fertilizers requires energy and it is estimated that fertilizer production accounts for about 45% of the energy; used in agriculture worldwide; 73% of which is used for the manufacture of N fertilize.

Energy Used For Fertilizer Production

The current energy crisis in the world has enhanced the prices of mineral fertilizers. So it has revived the interests in the use of green manures. The rising interest had led to the identification of some legumes that have high green manuring potential

Energy Crisis

1. Green manuring in-situ: When green manure crops are grown in the

field itself either as a pure crop or as intercrop with the main crop and buried in the same field, it is known as Green manuring In-situ. E.g.: Sunhemp, Dhancha, Urd, Mung, Cowpea, Berseem, Senji, etc.

Types of green manuring

2. Green leaf manuring: It refers to turning into the soil green leaves and tender green twigs collected from shrubs and tress grown on bunds, waste lands and nearby forest area. E.g.: Glyricidia, wild Dhancha, Karanj.

Types of green manuring

Legumes cowpeas Soybeans sweet clover Vetch Millet sorghum

Main Green Manure Crops In The World

Berseem Janter Guara Sunhemp Senji

Main Green Manure Crops In The World

1. Pakistani Janter (Sebania aculeata) 2. Tropical Janter (Sesbania rostrata} 3. Guara (Cymopsis tetragonolobas} 4. Sunnhemp (Crotolaria juncea) 5. Mungbean (Vigna radiata) 6. Cowpeas (Vigna unguiculata]

Main Green Manure Crops In Pakistan

These crops are sown as: i) Main crop, ii) Inter row sown crop, iii) On bare fallow, depending upon the soil

and climatic conditions of the region.

Green ManureCrops Sown AS

Short Period Yield a large quantity of green material

within a short period. Quick Growing Be quick growing especially in the

beginning, so as to suppress weeds. More Leafy Growth Be succulent and have more leafy growth

than woody growth, so that its decomposition will be rapid.

Characteristics/desirable qualities of a good manuring

Nitrogen Fixation Preferably is a legume, so that atm. ‘N’ will

be fixed. Root System Have deep and fibrous root system so that

it will absorb nutrients from lower zone and add them to the surface soil and also improve soil structure.

Grow In Poor Soil Be able to grow even on poor soils.

Characteristics/desirable qualities of a good manuring

A green manuring crop may be turned in at the flowering stage or just before the flowering. The majority of the G.M. crops require 6 to 8 weeks after sowing at which there is maximum green matter production and most succulent

Best Time For green manuring

When the crop reach full bloom than With the help of sohaga fall all the green manure crop in the field,Then mix the crop with the help of rotavator and disc harrow and give irrigation to start the process of decomposition

Method of Green Manuring

Improve soil Structure Has positive influence on the physical and chemical

properties of soil. Organic Matter Helps to maintain the organic matter status of soil. Source of Food and Energy Serves as source of food and energy for the

microbes multiplies rapidly, not only decompose the GM and result in release of plant nutrients in available forms for use by the crops.

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Advantages of Green Manuring

Improve Soil Aeration Improves aeration in soils by stimulating

activities of surface film of algae and bacteria

Water Holding Capacity It improve water holding capacity of poor

soil.

Advantages of Green Manuring

Green manuring builds up soil structure and improves tilth

Promotes formation of crumbs in heavy soils leading to aeration and drainage

Increases the water holding capacity of light soils.

Form a canopy cover over the soil, reduce the soil temperature and prevents from erosive action of rain and water

Soil Structure and tilth improvement

Absorb nutrients from the lower layer and leave them in surface when ploughed

Prevent leaching of nutrients to lower layers. Harbour N fixing bacteria, rhizobia in root

nodules and fix atmospheric N (60 to 100 kg N/ha) Increase the solubility of lime phosphates,

trace elements etc., through the activity of the soil microorganisms and by producing organic acids during decomposition.

Fertility improvement of soils

Sesbania aculeata (daincha) applied to sodic soils continuously for four or five seasons improves the permeability and helps to reclaim.

Tamarindus indica has a buffering effect when applied to sodic soils.

Removal of soil problems

Increases the yield of crops to 15 to 20 % Vitamin and protein content of crop

increased It also control the pests.

Improvement in crop yield and quality

i) Under rain fed conditions, the germination and growth of succeeding crop may be affected due to depletion of moisture for the growth and decomposition of G.M.

ii) G.M. crop inclusive of decomposition period occupies the field least 75-80 days which means a loss of one crop.

iii) Incidence of pests and diseases may increases if the G.M. is not kept free from them.

Disadvantages of green manuring