Best Soil-crop management  

Organic matter (humus) is the major part of soils; it must comprise of 3% weight age in soil.Unfortunately in Punjab soils, it reduces to less than 1%. Farmers applied heavy dose of synthetic fertilizers to exhaustive crops (Sugarcane, Maize & Rice) to get maximum returns that cause severe effects on soil structure and high soil pH. Farm yard manure, green manure and poultry manure are the least preference from farmer’s side now.

Most farmers outline that restorative crops and legumes can capture nitrogen from the air, so they shouldn’t apply manure. Now soils are usually deficient of many micro elements like boron, iron and zinc.

In this case manure is considered a good source of all these nutrients in balanced form.A crop requires a high nutrient need, phosphorus, potassium and sulfur, and micronutrients such as boron and iron for bumper production.

Restorative crops like alfalfa, soybean and other legumes can use nitrogen from the air with the assistance of rhizobia bacteria that live in the nodules on their roots; the plant will take available nitrogen out of the soil first.

This means legumes can help keep excess soil nitrogen in check and reduce the potential for nitrate leaching. Major sources of manures are:

1. Cattle shed wastes-dung, urine and slurry from biogas plants.
2. Town refuse, sewage, sludge and sullage.
3. Poultry Jitter, droppings of sheep and goat.
4. Slaughterhouse wastes-bone meal, meat meal, blood meal, horn and hoof meal, Fish wastes.
5. Byproducts of agro industries-oil cakes, bagasse and press mud, fruit and vegetable processing wastes etc.
6. Crop wastes-sugarcane trash, stubbles and other related material.
7. Dry weeds and tank silt.
8. Green manure crops and green leaf manure material.

There are three general manure application strategies or times of application: pre-plant (apply before seeding), top-dressing on established alfalfa and following last harvest at termination of the stand.

 Applying manure before plantation show good results. Pre-plant manure application will provide the most benefit on low-fertility soils. Usually experts recommend manure application in empty fields at the end of summer or monsoon season. Main advantage of applying fertilizer in that season is

a) Low temperature (slow down decomposition)
b) Minimum rain fall (Leach down of nutrition’s)
c) Available in field for long time
d) No stress affect to plants
e) Minimum weeds growth

 Yields from manure are sometimes even greater than those from potassium and phosphorus commercial fertilizer, perhaps because of other manure nutrients (sulfur, micronutrients) or soil physical or microbial
effects.

 Top-dressing is the second method to spread manure in field but not considered good in standing crops, however give good responses in grassy lawns. Top dressing in high temperature or in
suffocated weather can be harmful for the crop due to heat stress.

 The third application strategy is to apply manure following the last harvest at termination of the legume or grass stand (before plough down). This timing avoids any possible damage to the perennial forage crop. But, he said, it is important to limit application rates to the nitrogen need of the succeeding crop, accounting for both manure N and legume credit.

In case of Rhodes grass.and Alfalfa fodder in Punjab, last cut is almost harvested in November. Perennial crops usually remain in field for many years, so mostly in 2nd & 3 rd year, crop plant nutrition’s lose down to many folds with passage of every cuts.

Recommendations
1. Manure can carry pathogens, several protozoa and weed seeds. To minimize these concerns, experts encouraged spreading manure as soon after harvesting a crop as possible.

In new field, spread manure nearly two weeks before sowing. It gives immense time to grow all weeds before sowing and overcome the costing of herbicides.

2. Due to utilization of synthetic same chemical fertilizer for long run, salinity is going a giant concern. To defeat this, manure application every year is obligatory to maintain the soil pH.

3. Salt affected land show good results by applying manure regularly.

4. Improve soil physical properties like structure, water holding capacity

5. Plant parasitic nematodes and fungi are controlled to some extent by altering the balance of microorganisms in the soil

6. Carbon dioxide released during decomposition acts as a CO2 fertilizer

7. Gypsum is applied to reclaim the salt affected soils before manure application.


May 2015

By Muhammad Salman Naeem
Source: Pakissan Team