R. N. Adhikari , M. S. Rama Mohan Rao , A. K. Singh , K. K. Reddy

Abstract

Vegetative measures for soil & water conservation are preferred due to their efficacy and cost effectiveness. A study conducted during 1996-2000 in black soil semi-arid region showed that among the commonly occurring grasses, Cenchrus ciliaris, Dichanthium annulatum and Cymbopogon martini were most effective in reducing surface runoff which ranged from 9 to 12%, while sediment loss varied from 500 - 1000 kg/ha and was below permissible limits of 5 t/ha/year. Cymbopogon has drought resistance and capability to withstand limited grazing. It also gives comparatively more (1.7 to 2.4 times) biomass production with aromatic uses. Thus, from a holistic perspective Cymbopogon is recommended for conservation and production. By artificial seeding on large scale, Cymbopogon, Ciliaris and Dichanthium can replace the Sehima species which has currently failed to survive due to changed environment.

Keywords

Grass Species, Run-off, Soil Loss, Semi-arid, Black Soil

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A. Raizada , M. S. Rama Mohan Rao , K. T. N. Nambiar , M. Padmaiah

Abstract

Biomass prediction models were prepared for 17 year old Acacia nilotica trees raised on salt affected vertisols of the semi arid tropics in Karnataka. A. nilotica was raised at 8×8 m spacing with an under storey of three grass species - Cenchrus ciliaris, Dicanthium annulatum and Chloris bourneii for the production of fodder. Wide variations occurred in the trees sampled by random selection in the plantation, with respect to diameter (3.1 to 16 cm) and tree height (3.5 to 5.1 m). Leaf biomass varied from 0.5 to 3.1 kg/tree, contribution by big branches (> 2 cm dia.) varied from 3.81 to 24.13 kg/tree. Total above ground biomass ranged from 26.5 to 100.74 kg/tree. Prediction models with the best fit were in the linear form with r² values of 0.8261, 0.9162 and 0.8665 for predicting bole, utilizable and total above ground biomass.

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R. N. Adhikari , M. S. Rama Mohan Rao , V. Husenappa

Abstract

The rainfall simulator is an useful tool to generate quick and satisfactory information on runoff and soil loss under different surface conditions, involving much less cost and time. The results show that sorghum stover mulch reduced runoff and soil loss considerably. It is also observed that runoff and soil loss increase with increase in degree of slope. Simple application of mulch material on the surface upto 2% slope of the field, involving almost no cost, can act as good inter-terrace soil and water conservation treatment in the black soil region, apart from improving in-situ moisture condition to increase crop production. The results show that mulched plot reduced runoff by 10 to 20% in comparison to bare plot and for individual storm, soilless is reduced from 0.5 t/ha to 0.1 t/ha (for 1% slope) and 0.8 t/ha to 0.2 t/ha (for 2% slope). Attempt has also been made to have effect on runoff and soil loss under steep slopes having stone barrier using mini rainfall simulator. It is observed that stone barrier reduced sediment density by about 50%. From discharge simulation studies it is observed that grass cover reduced runoff and the peak rate of runoff by 20 to 30%. The study shows that simple and cheap technology like surface mulch, grass cover and stone barrier can act as a good soil conservation treatment in arable and non-arable land.

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M. S. Rama Mohan Rao , M. Padmaiah , A. Raizad , B. Ayyappa

Abstract

Multiple benefits which could be derived over a short period of time, after adopting various practices of floriculture, horticulture and tree plantations, on non-arable lands, in the semi-arid zones of Southern India are presented in this paper. Jasmine (Jasminium sambac Ait.) cultivation along river bank, is a profit-able activity, while application of DAP on grasses established over barren hill slopes, significantly increased dry matter yields. Tree plantations carried out along canal banks were better than those planted on hills, although tree survival on hill slopes was 40% and satisfactory.

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R. N. Adhikari , M. S. Rama Mohan Rao , I. P. Pradhan , M. Padmaiah

Abstract

The loss of soil, which constitutes one of the most important life supporting systems, results in lowering productivity and if unchecked may even threaten the very existence of life. Apart from reduction in productivity and destruction of valuable forests, it also reduces basin retention capacity causing floods in the down stream side and siltation of multipurpose reservoirs should be considered as non renewable and hence need to be protected on priority. It is therefore, essential to adopt proper conservation measures which are most effective and 1east expensive. Accordingly, studies were initiated since 1986, in two mine areas, namely (a) Navalutti Mines near Sandur (60 km from Bellary) under lease of M/s H.R.. Gaviappa & Co., and (b) Metriki Forest (Karnataka Forest Department). Vithalapuram Mine situated at 30 km on the south-west direction from Bellary.

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