Question

iv. Out of manures and fertilizers, which one has better water holding capacity? Give
the reason for your answer.​

Answer 1

Answer:

Environmental Benefits of Manure Application

Increased soil carbon and reduced atmospheric carbon levels.

Reduced soil erosion and runoff.

Reduced nitrate leaching.

Reduced energy demands for natural gas-intensive nitrogen(N) fertilizers.

Manures are prepared by the decomposition of dead plant and animal wastes e.g., plant residue, human waste, and cow and buffalo dung. Manures contain large quantity of organic matter and small quantity of nutrients. The bulk of organic matter in manure helps in improving soil fertility. So manures are also called natural fertilizers.

Manures are considered better than fertilizers in maintaining soil fertility due to

(i) Manures improve the structure of soil such as increase water-holding capacity in sandy soils. In clay soils, the large quantities of organic matter helps in drainage and avoiding water-logging in the fields.

(ii) Soil has various type of microorganisms which help to improve the fertility of soil. Excessive use of fertilizers harm these microorganisms and the soil tend to become unfertilized. Due to these reasons, we should prefer manure over fertilizers.

Answer 2

✦QuestioN :

✳ Out of manures and fertilizers, which one has better water holding capacity? Give the reason for your answer.

✦ExplanatioN :

☛Soil scientists report that for every 1 percent of organic matter content, the soil can hold 16,500 gallons of plant-available water per acre of soil down to one foot deep.

☛That is roughly 1.5 quarts of water per cubic foot of soil for each percent of organic matter, according to Sullivan in "Drought Resistant Soil. Agronomy Technical Note.

☛Appropriate Technology Transfer for Rural Areas" at the National Center for Appropriate Technologies in 2002.

☛Increasing the organic matter content from 1 to 2 percent would increase the volume of water to 3 quarts per cubic foot of soil.

☛Rodale Institute presenters, on the other hand, assume that 1 pound of carbon can hold up to 40 pounds of water.

☛That calculates out to be approximately 38,445 gallons of total water per acre six inches deep.

☛The point here is that organic matter holds a lot of water, thus, the amount of organic matter in a soil directly influences the availability of water to a crop over time.

☛However, organic matter in droughty soils breaks down so rapidly that getting above 2 or 3 percent is difficult to do, but getting to 2 to 3 percent can have major positive impacts.