SOIL GEOGRAPHYGGY - 428

S.Lathiscumar,

A/11/427,

Department of Geography,

University of Peradeniya.

Topic:Soil conservation method - Biological

Content• Introduction

• Biological conservation methods

– Contour farming

– Crop rotation

– Strip cropping

– Choice of crops

– Mulching

– Cover crops

– Reforestation

– Mixed crops

– Wind breaks

• The important of biological method in soil conservation

• Conclusion

• Reference

1.1 What is the soil?

o Soil is a thin layer of the Earth’s Crust.

o Formed by mineral particles, organic matter,

water, air and living organisms.

1.2 What is the soil conservation method?

Soil conservation method is a set of management strategies for prevention of

soil being eroded from the Earth’s surface or becoming chemically altered by

overuse, acidification, salinization or other chemical soil contamination.

Soil conservation method

Mechanical Biological

1. INTRODUCTION

2. Biological Conservation method

Biological conservation method is various ways of maintaining a cover of vegetation

during the periods of high erosion risk.

Biological method are an effective method of soil conservation.

Several types of biological soil conservation methods exist. Those are:

• Contour farming

• Crop rotation

• Strip cropping

• Choice of crops

• Mulching

• Cover crop

• Reforestation

• mixed crop

2.1 Contour Farming

Contour farming is the farming practice of planting across a slope following it elevation

contour lines.

Farming on the contour creates small ridges that slow runoff water, and it increases the

rate of water infiltration, reduces the hazard of erosion.

2.2 Crop Rotation

The change type of plant grown on particular piece of land from year to year or

season to season.

Intercropping of erosion permitting crops and erosion resisting crops or their rotation.

Has been found effective for reducing soil loss.

Return nutrients to soil.

2.3 Strip Cropping

Strip cropping is a method of farming used when a slope is too steep or too long.

Strip cropping helps keep the soil in a long enlarge of land.

this method becomes more effective for erosion control.

the strip crops check the surface runoff and force them to infiltrate into the soil, thereby

facilitates to the conservation of rain water.

2.4 Choice of crops

Choice of crop is select the erosion resisting crops and cultivate.

Row crops or large growing crops such as sorghum, maize, pearl millet is not

protective in conserving soil.

Whereas close growing crops such as cowpea, groundnut, green gram, black gram

etc., Those crops are soil erosion resisting crops. Then they very effective in reducing

soil loss.

2.5 Mulching

Mulching of soil with available plant residues reduce soil loss considerably by protecting

the soil from direct impact of raindrop and reducing the sediment carried with runoff.

A minimum plant residue cover of 30 per cent is necessary to keep runoff and soil loss

within the acceptable limits.

Vertical mulching also reduce soil loss

and increasing infiltration.

2.6 Cover cropping

cover cropping is good ground cover by canopy gives the protection to the land and

minimize soil erosion.

Then conserving soil and moisture, the cover crops hold those soluble nutrients, which

are lost by leaching.

The advantage of the cover crops is the addition of organic matter.

The legumes provide better cover and better protection.

2.7 Reforestation

Reforestation involves the replanting or regeneration of areas of forest which have

previously been damaged or destroyed.

Forest mainly control the splash erosion. for the reason that plant canopy

decrease raindrop velocity.

2.8 Mixed cropping

Mixed cropping is the cultivation of more

than one type on a piece of land at the same time.

E.g. Corn and sugar beet.

Here different kind of plants need different

level nutrition. Hence soil nutrition isn’t severe losses.

Then harvest periods are different. Because different kind of plants. Always

cropping cover the surface. So soil erosion can control with mixed cropping.

2.9 Wind breaks

Wind break is a wind barriers created by planting trees that produce may

branches and leaves.

This method is used at the edges of large farmland area to stop the wind from

blowing soil away.

3. The important of biological method in soil conservation

Maintain productive topsoil.

Keep food safe and healthy.

Reduce chemical fertilizers and pesticides.

Keep farms economically possible.

Sustainable options mimic past practices.

prevents splash erosion and reduces the velocity of surface runoff.

facilitates accumulation of soil particles.

Increase infiltration.

4. Conclusion

Biological method of soil conservation is various ways of maintaining a cover of

vegetation during the periods of high erosion threat.

Contour farming, crop rotation, strip cropping, choice of crops, mulching, cover

crop, reforestation, mixed crop, wind breaks are major biological soil conservation

methods.

Biological method are an effective method of soil conservation. For the reason

that low cost.

Biological method of soil conservation is reduce the surface runoff, increase the

infiltration and reduce the soil erosion.

5. Reference

Bennett, H. H., (1947) Elements of Soil Conservation, McGraw – Hill Book Company,

Inc, New York AND London.

http://www.arkive.org/reforestation/

https://www.blog.udemy.com/soil-conservation/

http://www.brighthub.com/environment/science-environmental/articles/82947.aspx

http://www.fao.org/docrep/004/y0501e/y0501e03.htm

http://www.preservearticles.com/2012040429881/what-are-the-methods-of-soil-con

servation-18-methods.html

http://www.teara.govt.nz/en/soil-erosion-and-conservation/page-7