Agro-Forestry- SURYAKANTA BEHERA

Agroforestry: A suitable System for Soil Health Enhancement

SURYAKANTA BEHERA

Department of Agronomy, MS SWAMINATHAN school of Agriculture

Centurion University of Technology & Management

                  

                                             E mail: suryakantarrr@gmail.com

Introduction:

Agro-forestry is recognized as a land use option in which trees provide both products and environmental services. In agroforestry systems, the trees grown on different farmlands in the same locality when aggregated can bring about improved wooded situation thereby enhancing environmental protection (Otegbeye, 2002). Land degradation was a significant global issue during the 20th century and remains of high importance in the 21st century as it affects the environment, agronomic productivity, food security, and quality of life (Eswaran et al. 2001).However, human population growth and the need for agricultural expansion, in conjunction with wood harvesting for fuel and export, have led to increasing deforestation rates. Approximately 65 % of the land in the tropical world, which is home to over 630 million people, is susceptible to such degradation (King, 1979).

Role of Agroforestry in soil quality/heath:

Compared to natural, a managed agricultural ecosystem has greater amounts of nutrient flowing in and out, less capacity for nutrient storage, and less nutrient recycling. The capacity of trees to maintain or improve soils is shown by the high fertility status and closed nutrient cycling under natural forest, the restoration of fertility under forest fallow in 6 shifting cultivation, and the experience of reclamation forestry and agroforestry (Young, 2003).

The processes by which trees maintain or improve soil fertility are given below:

1. Photosynthetic fixation of carbon and its transfer to the soil via litter and root decay,

2. Nitrogen fixation by all leguminous trees and in few non-leguminous species (e.g., Alder and Casuarinas),

3. Improved nutrient retrieval by tree roots, including through mycorrhiza and from lower horizon,

4. Providing favourable conditions for the input of nutrients from rainfall and dust

5. Control of erosion by combination of cover and barrier effect, especially the former.

6. Root uptake of nutrients that would otherwise have been lost by leaching,

7. Soils under trees have favourable structure and water holding capacity, through organic matter maintenance and root action,

8. Provision of a range of qualities of plant litter, woody, and herbaceous,

9. Growth promoting substances,

10. The potential through management of pruning and relative synchronization of timing of release to nutrients from litter with demand for their uptake by crops, and

11. Effects of tree shading on microclimate.

Conclusion:

Agroforestry is an ecologically based, natural resources management system that sustains production and benefits all those who use the land by integrating trees on farms and in the agricultural land scape. In addition to provide timber, fodder, fuel wood, medicines, etc., it conserves soil and enhances soil fertility. Improvement in soil fertility takes place by the process of checking soil erosion and runoff, maintaining soil organic matter, enhancement of soil physical, chemical, and biological properties, increment of nitrogen input by N-fixing trees and shrubs, and mining of minerals from lower horizons by roots and its recycling through litter fall on ground.

Reference:

Dhyani, S.K. 1998. An Analysis of Agroforestry Systems on Crop Productivity and Soil Characteristics. Ph. D. Thesis, Department of Botany, North Eastern Hill University, Shillong, Meghalaya, pp. 220

Lal, R. 2001. Soil Degradation by Erosion. Land Degradation and Development 12: 519-539.

Patiram and Choudhury, B.U. 2002. Role of Agroforestry in Soil Health Management, ICAR Research Complex for NEH Region, Umiam – 793 103, Meghalaya.

Sharma, K.L. 2002. Effect of agroforestry systems on soil quality –monitoring and assessment. Central Research Institute for Dryland Agriculture, Santoshnagar, Hyderabad – 500059 .

Young, A. Agroforestry for Soil Management (2nd ed.). CAB International, Wallingford, UK.