1009-B5

Studies on Sodic Soils (Problematic Soils) Rehabilitation Through Agroforestry System for Central Plain Zone of Uttar Pradesh, India

S.A. Khan ¹

ABSTRACT

Enormous increase in human and cattle population created pressure on forest area to fulfill the requirement of fuel wood, timber, fodder and food, which resulted in huge deforestation of forest area (1.5 mha/year). In the same manner the forest area of Uttar Pradesh, India, is decreasing day by day for shake of food security, survival and shelter. To maintain the ecological balance in this area the forestry can only find place on sodic soils where no any crop can survive due to higher soil pH and electrical conductivity. The sodic soils cover an area of 1.2 mha in Uttar Pradesh, which may be rehabilitated by adoption of Agroforestry system. Keeping in view the seriousness of problem, the present studies entitled, "Studies on Sodic Soils (Problematic Soils) Rehabilitation Through Agroforestry System for Central Plain Zone of Uttar Pradesh, India" was undertaken at Regional Research Station, Dalip Nagar, C.S. Azad University of Agriculture and Technology, Kanpur (U.P.) India, during the year 1989. By the adoption of Agroforestry system the soil pH and EC was decreased upto 8.2 and 0.2 mmhos/cm, respectively after eight years experimentation. The soil organic carbon, available phosphorus, available potash was also increased. Among the tree species tested, Acacia nilotica, Albizia procera, Leucaena leucocephala, Azadirachta indica and Eucalyptus hybrids were found most suitable tree species for permanent rehabilitation of sodic soils and to maintain friendly eco-system.

INTRODUCTION

The land is limited entity of the country like ours which, compel us to increase production and productivity of land per unit area and to rehabilitate the problematic soils for crop production, forestation and to maintain friendly eco-system. In our country presently 175 mha land is subjected to various type of degradation out of which 9.38 mha suffered by sodicity and alkalinity. The sodicity of soil developed by accumulation of excessive salt in the upper surface of soil because of impermeable hard pan of calcium carbonate at a depth of 60 cm to 1.2 m. Under such category of soils the survival of crops are very difficult. The rehabilitation of sodic soils, through chemical and mechanical mean are very costly, so that it is the beyond the reach of Indian farmers. Under such soil condition trees may do well with crops to sustain the productivity of soils (Khan et al. 1995). The establishment of permanent vegetative cover of suitable trees, and herbaceous crop is an option of great promises for the use of such lands in view of growing demand for fuel wood, timber and fodder as well as environmental improvement.

MATERIAL AND METHODS

A field study was initiated during the year 1989 at Regional Research Station, Daleep Nagar, C.S. Azad University of Agriculture and Technology, Kanpur-208002 (U.P.), India. The soil of the experimental field was alluvial in nature and sodic in reaction with initial soil pH and electrical conductivity of 10.5 and 0.73 mmhos/cm, respectively. The soil possess poor drainage and a hard pan of calcium carbonate nodules at a depth of 60 to 120 cm which inhibited infiltration and percolation of harmful salt in the lower surface of soil. The soil was low in organic carbon, available nitrogen and potash and medium in phosphorus. The experimental area falls under sub-tropical semi arid climate with average rainfall of 800mm.

The experiment was planted during the month of August and September, 1989 (rainy season) in pits of 60cmx60cmx90cm size, filled with 3000g pyrite + 5000g compost + 10,000g sand and the soil of the same field. The experiment consist ten tree species viz. Azadirachta indica, Acacia nilotica, Acacia catechu, Eucalyptus hybrid, Dalebrgia sissoo, Albizzia procera, Leucaena leucocephala, Morus alba, Terminalia arjuna and Casia seamea and replicated four times in randomized block design. The plants were irrigated as when required and excess water was drained during rainy season. The plants were planted in the following plant geometry.

Table-1: Plant geometry

The soil samples of experimental field were collected twice in a year for chemical analysis. The growth observations of plant were recorded ones in a year during the month of December.

RESULTS AND DISCUSSION:

Table-2: Survival percentage, initial plant growth and plant growth during the year 2000, as influenced by tree species

Survival Percentage of Plants:

The survival percentage of tree species was appreciably influenced by the tree species tested. It is indicated from the Table-2 that cent percent plant survival was observed with Acacia nilotica followed by Albizia procera (98.6%), Terminalia arjuna (90.0%), Dalbergia sissoo (87.5%), Azadirachta indica (86.1%) and Leucaena leucocephala (85.4%), and was lowest with Morus alba (22.29%. These results corroborates with those of Banwari Lal & Khan (1994) and Mishra et al. (1998).

Plant Growth:

Height - It is revealed from the Table-2 that during the establishment stage of the plants the Leucaena leucocephala showed the highest plant height followed by Eucalyptus hybrid, Azadirachta indica, Dalbergia sissoo, Morus alba, Albizia procera and Terminalia arjuna and was lowest with Cassia seamea. The highest plant height with Leucaena leucocephala and Eucalyptus hybrid may be due to fast growing habit of these plants. In the later growth stages the Eucalyptus hybrid showed the highest plant height followed by Leucaena leucocephala, Acacia nilotica, Albizzia procera, Azadirachta indica, Cassia seamea and Acacia catechu and being lowest with Morus alba (Khan et al. 1994, Banwari Lal & Khan, 1994).

Girth - An remarkable variation in plant girth was indicated by the plant species. In the early stage of growth the maximum plant girth was accounted by the Leucaena leucocephala followed by, Azadirachta indica, Acacia nilotica, Albizia procera, Eucalyptus hybrid, Dalbergia sissoo and Cassia seamea and it was lowest with Terminalia arjuna where as at later stage of growth the Azadirachta indica attained the highest plant girth followed by Acacia nilotica, Albizia procera, Terminalia arjuna, Leucaena leucocephala, Acacia catechu and Dalbergia sissoo and was lowest with Morus alba. These results are in conformity with those of Anon (1998), Banwari Lal & Khan (1994) and Khan et al. (1995).

Chemical Properties of Soil -

Change in Soil pH and EC -

Tabel-3: Change in Soil pH and EC by different plant species.

The initial soil pH and EC of experimental field was 10.5 and 0.730 mmhos/cm, respectively in the year 1989 and it dropped upto 8.26 and 0.21 mmhos/cm, respectively during the year 2001. The drastic change in pH was observed during the year 1992 (9.00) as compared to previous year (1991). The lowest soil pH was recorded during the year 1998 (7.8) and it was slightly raised during the year 2000. The electrical conductivity of soil was also decreased remarkably by the adoption of agro-forestry system. It may be attributed due to leaching of harmful salt through roots of plants and by the decomposition of litters on the upper surface of the soil. Similar effect of tree species on soil pH and EC were reported by Goyal et al. (2001), Singh (1995) and Singh et al. (1997).

Nutrient Status of Soil:

Table-4: Chemical properties of soils as influenced by tree species.

It is revealed from the Table-4 that tree species plays an important role in respect of soil, pH EC, Organic carbon, available P and available K. Among the tree species tested Eucalyptus hybrid showed the lowest pH value (7.20) followed by Leucaena leucocephala, Albizzia procera, Cassia siamea, Acacia catechu, Morus alba, Azadirachta indica and Acacia nilotica and being higher with Terminalia arjuna. The lowest EC value was recorded by the Morus alba, Dalbergia sissoo, Eucalyptus hybrid, Leucaena, leucocephala, Acacia catechu, Acacia nilotica and Cassia seamea (0.2 mmhos/cm) followed by Azadirachta indica (0.25 mmhos/cm), Albizia procera (0.25 mmhos/cm) and Terminalia arjuna (0.26 mmhos/cm). The highest organic carbon was recorded with Acacia nilotica (0.85%) followed by Cassia siamea, Azadirachta indica (0.75%), Acacia catechu (0.67%) and Morus alba (0.57%) and being lowest with Albizia procera(0.45%). The available phosphorus was higher with Cassia siamea (23.4 kg/ha) followed by Acacia catechu, Morus alba, Dalbergia sissoo, Acacia nilotica and Azadirachta indica, and was lowest with Eucalyptus hybrid and Albizia procera. The higher available potash was noticed with Azadirachta indica (240 kg/ha) followed by Acacia catechu (225 kg/ha), Morus alba, Dalbergia sissoo and Leucaena leucocephala and was lowest with Albizia procera (125 kg/ha). The increase in organic matter, available P and K of soil by trees have been reported by Goyel et al. (2001).

CONCLUSION:

It is concluded that sodic soil can be permanently rehabilitated by the adoption Agroforestry system, to supplement the requirements of fuel wood, fodder and timber to the farmer's and to maintain friendly eco-system in the area.

REFERENCE:

Anonymous (1998). Annual Report, IGFRI, Jhansi.

Banwari Lal and Khan, S.A. (1994). "Technology for salt affected soil of Central U.P." proceeding of "National Symposium on Research Management and crop productivity" held at Haryana Agriculture University, Hisar from Feb 16-18, 1984.

Goyal et al. (2001). Soil organic matter and soil microbial properties in Melia azadirach plantation in salt affected soil. Ind J. Agroforestry 3 : 2, 130-133.

Khan, S.A.; Yadav, V.K. and Shukla, I.N. (1995). "Screening of tree species in relation to crop and higher biomass production under Central U.P. Proceeding of Seminar on Agroforestry for higher crop and biomass production organized by NRCAF, Jhansi from March, 24-25, 1995.

Mishra, C.M. (1990). Growth behviour of certain multipurpose tree in saline alkaline soil. Proceedings of the "National Workshop on Multipurpsoe. Tree species for Agroforestry System" held at IGFRI, Jhansi, from Feb 1-3, 1990, pp. 133-135.

Singh, G. (1995). An agroforestry practices for the development of salt lands using Prosopis Juliflora and Leptochlova fusca. Agrofor. Syst. : 29 : 61-75.

Singh, G., Singh, N.T. and Abrol, I.P. (1994). Agroforestry techniques for the rehabilitation of salt affected soils of India. Land Degr. Rehabil. 5 : 223-242.

¹ Principal Scientist (Agroforestry)
C.S. Azad University of Agriculture and Technology, Kanpur-208002 (U.P.), India.