Green manuring is the practice of enriching soil fertility by plowing under or incorporating green manure crops into the soil while still green or soon after flowering. It improves soil structure and fertility by adding nutrients like nitrogen. Common green manure crops in India include dhaincha, glyricidia, and karanja, which are plowed under at the flowering stage. The benefits of green manuring include increased organic matter, improved soil structure, increased nutrient availability and crop yields. Proper timing and crop selection is important for effective green manuring.
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Green manuring
2. GREEN
MANURING
SUBMITTED TO: Dr. Rajesh Meena
(Scientist NDRI karnal)
ICAR-NDRI
SUBMITTED BY: Pramod Kumar Tiwari
M.Sc.(Agronomy)
3. INTRODUCTION
Green manuring is a part of organic farming which can be
defined as the practice of enriching the soil fertility by
ploughing under or soil incorporation of any green manure
crops while they are green or soon after they start
flowering.
Green manuring is considered to be a good management
practice in all agricultural production systems because of
its increasing sustainability of cropping system through
reducing soil erosion.
The crops that are grown for green manure are called green
manure crops.
4. WHAT IS GREEN MANURE?
Green manure refers to a plant material
incorporated with the soil while green or
soon after maturity for improving the soil
to supply nutrients, particularly N, to a
standing crop.
WHAT IS GREEN MANURING?
Green manuring is a practice of ploughing or
burying the undecomposed green plant tissues
into the soil for improving structure and fertility
of the soil.
5. STATUS OF GREEN MANURING CROPS IN INDIA:
At present only 6.7 mha area is green manured which accounts for 4.5% of
NSA (142mha) of the country .
The practice is most common in rice growing states like AP,UP,KN,PB
and Odisha which contribute 41,16,11,6 and 5% respectively to the total
area under green manuring in India .
6. DESIRABLE CHARACTERISTICS OF GREEN
MANURING CROPS:
Multipurpose.
Short duration as well as fast growing .
High nutrient accumulation ability.
Tolerance for adverse climatic condition.
High water use efficiency .
Early onset of BNF.
High seed production.
Long seed viability .
Ease in incorporation
Pest and disease resistant.
Deep root system.
High biomass production .
Wider ecological adoptability.
7. TYPES OF GREEN MANURING
Green-manuring can be done in 2 ways depending on the
situation.
Green-manuring in situ: This is the growing and
burying of a green manure crop in the same field as
the one to be manured.
Green-leaf manuring: GLM refers to turning into the
soil green leaves and twigs collected from shrubs and
trees grown on bundhs, wastelands or nearby forest
Areas.
15. ADVANTAGES OF GREEN MANURING
Green manures add organic matter to the soil and simulates
activity of soil microorganisms.
Green manures improve the structure of the soil thereby
improving WHC, decreasing run off and erosion.
Green manures take nutrients from lower layers of the soil
and adds to the upper layer of soil.
Green manures increase the availability of certain plant
nutrients like NPK.
Green manures improves soil structure and soil tilth.it also improves
areation in rice soils by stimulating the activities of surface film of algae
and bacteria.
Green manuring increases the yield of crops to an extent of 15-20% as
compared to non green manuring fields.
16. LIMITATIONS OF GREEN MANURING
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 green manuring.
Green manuring crops inclusive of decomposition period occupies the
field least 75-80 days which means a loss of one crop.
Incidence of pests and diseases may increases if the green manuring is not
kept free from them.
A green manure crop may compete for time, labour and water, the cost of
which must be balanced against the cost of inorganic fertilizers.
Non availability of good quality seeds restrict raising of green manure
crops.
17. WHY GREEN MANURING?
Indian soils are deficient in Nitrogen and Phosphorus and there
is hardly any soil from which yield can be obtained without
fertilization.
18. AGE OF INCORPORATION
Green manure crop should be incorporated into soil at proper
age of crop to get maximum benefit. It should be turned into
soil at flowering stage, which is about 7-8 weeks after sowing.
Dhaincha attain maximum growth about 8 weeks after
sowing, while sun hemp crop flower aroung 8-10 weeks after
sowing. An 8 week old green manure crop is succulent enough
to be turned into soil for best response under rice.
Various reports conclude that a green manure crop should be
turned under at 7 to 8 week age, which coincides with flowering
and maximum growth stage for most of the green manure crops.
19. PRINCIPLES OF GREEN MANURING
Which green manure crop should be grown (best suited to the soil and
climatic condition)
When should be grown (time of sowing)
At what stage it should be buried (time/stage to turned into soil)
What should be the time lag between the burying of the green
manure crop and the sowing of the next crop (to allow decomposition)
Green manure crop should be raised by using higher seed rate than
usual grain crops so that there may be quick good canopy development
as well as good biomass production .
20. BROWN MANURING
Brown manuring was started in Australia in 1996 at new south weles.Brown
manuring is a technique to grow Sesbania in standing rice crop and kill them with
the help of herbicide for manuring. After killing the color of the sesbania residue
become brown so it called brown manuring.
Brown manuring practice introduced where Sesbania crop @ 20 kg/ha is
broadcasted three days after rice sowing and allowed to grow for 25-30 days and
was dried by spraying 2,4-D ethyle easter @.5Kg/ha either bispyribac-
Na(nominee gold)@20-25gm which supplied upto 15-20 Kg N/ha with a fresh
biomass of 10-12 t/ha.
This practice can be fallowed in crop like maize, pearl millet, sourghum.in broad
leaved crop like soyabean 2,4-D can not be used, but sesbania can be cut manually
and spread as mulch between crop rows for controlling weed and conservation of
moisture and nutrient.
23. ADVANTAGES OF BROWN MANURING
OVER GREEN MANURING:
Organic matter tends to be preserved.
Saving of fuel and labour costs.
There is potentially better weed control.
The risk due to erosion is reduced.
More soil water is conserved.
24. CONCLUSION
Green manuring technology is gaining importance due to
increasing emphasis on soil health, minimize environmental
pollution and cut down the use of chemical in agriculture.
Application of green manure crops supplements the
chemical fertilizers and restores soil fertility. Therefore, it is
an eco-friendly low cost technology to conserve the natural
resources besides maintaining environmental quality in a
sustainable manner By raising or incorporation of green and
green leaf manures the soil fertility can be improved.
Low cost practice and an alternate way to improve soil
fertility status.
25. References :
Principles of agronomy,(S.R. Reddy).
Text book of plant nutrients & management,( ISA).
Modern concept of agronomy ,(ISA).
ANGRAU manure & fertilizer module.
Google , Wikipedia.
Editor's Notes
#4: Green manuring is a part of organic farming which can be
defined as the practice of enriching the soil fertility by
ploughing under or soil incorporation of any green manure
crops while they are green or soon after they start
flowering.
Green manuring is considered to be a good management
practice in all agricultural production systems because of
its increasing sustainability of cropping system through
reducing soil erosion.
The crops that are grown for green manure are called green
manure crops.
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