*4.4.1 Contour cultivation*

When tillage operations are carried out along the slope, the flow of generated runoff is accelerated, because each furrow serves as a rill which results in more runoff and soil erosion. Carrying out the farm operations such as plowing, seeding, planting and inter-culture operation along the contour or across the slope helps in formation of natural ridges and furrows which act as series of mini barriers and reservoirs to intercept rainwater and reduce runoff, soil and nutrient losses. In Shiwalik foothills, contour cultivation reduced runoff by 20.6%, soil loss by 43.5% and increased maize yield by 23% [24].

#### *4.4.2 Strip cropping*

It is the system of growing of erosion permitting crops (Maize, Sorghum, Pearl millet, Cotton etc.) and erosion resisting crops (Green gram, Black gram, Moth, Groundnut etc.) in alternate strips of suitable width across the slopes on contour in the same field. It helps in reducing the slope length, reducing velocity of runoff, arresting soil by provide a vegetative filter and increasing opportunity time for infiltration of rainwater into the soil profile. In Doon valley, strip cropping of Maize and Cowpea in 2:1 ratio has been reported to reduce runoff from 43 to 37% and soil loss from 21 to 11 Mg/ha [25].

**189**

*Ecological Engineering Measures for Ravine Slope Stabilization and Its Sustainable Productive…*

The growing of low stature legumes like Groundnut, Cowpea, Green gram and Black gram in wider inter-row spaces of crops like Maize, Sorghum and Castor simultaneously on the same piece of land with a definite row-planting pattern is known as intercropping. It provides sufficient cover on the ground and thereby reduces soil erosion in shallow ravines. Intercropping offers an opportunity for profitable utilization of available space. Intercropping of Castor + Green gram (1:2) in South-Eastern Rajasthan reduced runoff by 22% and soil loss by 30% as compared to sole castor, apart from improving soil fertility status and improving crop yield. The system has been found ideal under aberrant conditions such as late onset of monsoon where it recorded only 15% reduction in productivity against 48–50%

It is one of the most important agronomic practices which not only reduces evaporation losses, runoff, and soil erosion but also increases infiltration, improves of soil structure and regulates of soil temperature. In low rainfall areas, mulching helps in conserving moisture in the soil profile while in high rainfall areas, it reduces runoff and soil losses, in turn, are reflected in higher productivity. A study conducted at Chandigarh in Shiwalik region of Northern India indicated possibility of increasing Wheat yield by 58% by providing grass mulch during *Rabi*. In another study conducted at Dehradun, recycling of Sun hemp *in-situ* as mulch one month after sowing reduced runoff and soil loss and significantly increased yield of succeeding Wheat crop [24]. At Kanpur in Northern India, rice straw mulch increased yield of maize by 41.8% and mustard by 190%. Mulching can reduce erosion on slopes of 25–39%. In tea garden the mulching with Guatemala grass (*Tripsacum laxum*) at the rate of

Tillage modifies the soil physical characteristics i.e. bulk density, surface rough-

Soil erosion depends on cropping system adopted on the land. The growing of crops which produce maximum cover, reduce runoff and soil loss always better for soil erosion point of view. Cowpea and Green gram are important cover crops for the rainy seasons. They provide early and dense (85%) ground cover which

ness, porosity and hardness of pan. The conventional tillage leaves no land unplowed and leaves no residues on the field. In the Indo-Gangetic plains of Yamuna river, where rain water cannot enter into deeper layers due to presence of impervious soil layer (*Kankar*) and is lost as runoff, deep tillage by disc plow once in three years up to 20 cm depth and one pass of cultivator every year helped in reducing runoff considerably and enhanced grain yield of pearl millet by 50%. Conservation tillage involves disturbing the soil to the minimum extent necessary and leaving crop residues on the soil surface. It ensures at least 30% coverage of the soil surface with crop residue which play a very important role in organic carbon build up and soil and moisture conservation under dry land. In Maize-Toria cropping system of the hill and mountain agro-ecosystem, Minimum Tillage + Crop residue incorporation is effective in reducing runoff by 12% and soil loss by 24% as compared to the

37 Mg/ha reduced the soil loss from 9 Mg/ha to 7 Mg/ha [27].

conventional tillage besides minimizing nutrient losses [28].

*DOI: http://dx.doi.org/10.5772/intechopen.94136*

reduction in other systems [26].

*4.4.5 Conservation tillage*

*4.4.6 Cropping system*

*4.4.3 Intercropping*

*4.4.4 Mulching*

*Ecological Engineering Measures for Ravine Slope Stabilization and Its Sustainable Productive… DOI: http://dx.doi.org/10.5772/intechopen.94136*

### *4.4.3 Intercropping*

*Slope Engineering*

degraded ravine agro-ecosystems.

**4.4 Agronomic measures for management of ravine**

ing, tillage and other improved practices [23].

and increased maize yield by 23% [24].

*4.4.1 Contour cultivation*

*4.4.2 Strip cropping*

loss from 21 to 11 Mg/ha [25].

Sapota trees may induce soil loss on ravine slope [3]. Supporting native or improved perennial grasses instead of crops may be a better option to reduce the soil erosion. Most researchers have concluded that incorporating trees in agriculture landscape conserve soil and water resources in ravine lands. In these conditions, extreme weather condition also affects plant growth and productivity and hence crop failure is a big problem. Tree-crop combinations system can be win-win situation in these climatically and edaphically venerable degraded agro-ecosystem. Tree and grass systems are also considered to be more resilient compared to crops during extreme weather conditions. Incorporating trees agriculture system also results in higher carbon stock and sequesters maximum carbon, compared to sole cropping systems. The CO2 mitigation in agroforestry is approximately 11–41% higher compared to sole cropping systems. The farmers in ravine should shift from annual crops to perennial plantations to conserve soil resources, avoid risk of crop failure and mitigate climate change. Moreover, a properly managed agroforestry systems can moderate/improve climatic conditions, conserve soil and water resources, improve ecosystems services and absorb atmospheric GHG's in ravine lands. This suggested agroforestry based farming systems should be preferred globally in

Agronomic measures are being considered as second line of defense in soil and water conservation however, these are of immense importance perhaps much more than other practices. These measures are recommended on mildly sloping lands (1–6%) for conservation of rainfall for sustainable production. They help in intercepting rain drops by decreasing the amount, intensity and the spatial distribution of the precipitation reaching the soil surface and protects the soil surface from the direct impact of raindrops which can cause a splash and sheet erosion. They also help in increasing infiltration rates and thereby reduce runoff and overland flow. These measures include contour cultivation, strip cropping, intercropping, mulch-

When tillage operations are carried out along the slope, the flow of generated runoff is accelerated, because each furrow serves as a rill which results in more runoff and soil erosion. Carrying out the farm operations such as plowing, seeding, planting and inter-culture operation along the contour or across the slope helps in formation of natural ridges and furrows which act as series of mini barriers and reservoirs to intercept rainwater and reduce runoff, soil and nutrient losses. In Shiwalik foothills, contour cultivation reduced runoff by 20.6%, soil loss by 43.5%

It is the system of growing of erosion permitting crops (Maize, Sorghum, Pearl millet, Cotton etc.) and erosion resisting crops (Green gram, Black gram, Moth, Groundnut etc.) in alternate strips of suitable width across the slopes on contour in the same field. It helps in reducing the slope length, reducing velocity of runoff, arresting soil by provide a vegetative filter and increasing opportunity time for infiltration of rainwater into the soil profile. In Doon valley, strip cropping of Maize and Cowpea in 2:1 ratio has been reported to reduce runoff from 43 to 37% and soil

**188**

The growing of low stature legumes like Groundnut, Cowpea, Green gram and Black gram in wider inter-row spaces of crops like Maize, Sorghum and Castor simultaneously on the same piece of land with a definite row-planting pattern is known as intercropping. It provides sufficient cover on the ground and thereby reduces soil erosion in shallow ravines. Intercropping offers an opportunity for profitable utilization of available space. Intercropping of Castor + Green gram (1:2) in South-Eastern Rajasthan reduced runoff by 22% and soil loss by 30% as compared to sole castor, apart from improving soil fertility status and improving crop yield. The system has been found ideal under aberrant conditions such as late onset of monsoon where it recorded only 15% reduction in productivity against 48–50% reduction in other systems [26].
