Towards a green economy

Table 4 shows that investment costs in drip irrigation systems and in manual treadle pumps are recovered more quickly; returns to investments have on average been more than 10-fold. These technologies have demonstrated their effectiveness in reducing income vulnerability and uncertainty for small-holder farmers across the continent. Drip irrigation systems also allow the more efficient use of water and are particularly useful for multiple cropping; in Nepal women farmers have been able to earn additional incomes by growing high value crops on otherwise barren land. Strategies such as the use of drought-resistant varieties of crops mainly involve investment in research and distribution of new seeds. In this context, estimated returns on investment are an order of magnitude higher, especially as witnessed in water-starved regions of Africa.

The success of these strategies also implies that agronomic research and development on improving water management practices in rain-fed agriculture and on tilling practices has been successful although much more is required. A strategy that remains relatively

Strategy Cover mulch Crop and country

Grain in India (Sharma et al. 1998); Groundnut in India (Ghosh et al. 2006).

Costs

In groundnut cultivation the cost of wheat straw mulch was US$ 58/ha. Cultivation required 5 tonnes of mulch per hectare. Black plastic covers cost much more (US$ 1.8 /kg, vs. straw at US$ 0.01/kg).

untapped is community-led watershed management. Watershed management has conventionally meant large hydraulic engineering efforts that are applied to local streams or river basins to establish a network of water reservoirs, catchment areas and other water impoundment and storage infrastructures. However, community-led watershed management strategies that protect and improve soil, water and plant resources in a catchment area are rapidly gaining traction and are rapidly becoming a lucrative opportunity for farmers who can benefit from Payment for Ecosystem Schemes (PES). These community led watershed management strategies offer important opportunities for increased efficiencies in irrigation (Krishna and Uphoff 2002).

As far as crop and livestock diversification is concerned, genetic resources for plant and animal breeding are the basis for food production. Genetically diverse crops can combine the best traits of local varieties of crops derived from indigenous species and other higher yielding varieties. Similarly, selecting and mating local animal breeds with high-performance breeds increases

Benefits

Average yields for grain and straw were the highest in fields that received cover mulch of 6 tonnes/ha: Yields increased by 130-149% over 3 years. Using wheat straw mulch cover increased pod yield of groundnut by 17–24%. Using both– wheat straw mulch and black plastic covers led to yield increases of 30 to 86% across test fields.

Furrow contouring

Corn in China (Li X. et al. 2001).

Manual treadle pump

Major staples including cassava, maize, rice and yam in Ghana (Adeoti et al. 2007 and 2009) and a variety of crops, Zambia (Kay and Brabben 2000).

Technique used plastic covers and constructed furrows. Costs of plastic and labour are not provided.

Depending on region the cost of a manual treadle pump in Ghana was US$ 89. Users had to pay additionally for labour. Total production costs increased by US$ 162/farm on average. In Zambia the cost of suction pumps ranged from US$ 60–77 and cost of pressure pumps was US$ 100–120.

Drip irrigation

Vegetables in Nepal (Upadhyay 2004) Maize and vegetables in Zimbabwe (Maisiri et al. 2005).

Using low-water varieties of crops

Maize varieties in 13 countries of eastern, southern and West Africa (La Rovere et al. 2010).

On average farmers had to pay US$ 12/farmer in Nepal for drip irrigation system (perforated tubing and a suspended water container).

US$ 76 million was invested in cultivating low-water varieties of crops over 10 years in these countries.

Corn yields increased by 60-95% during drought years, 70-90% in wet years and 20-30% in very wet years.

In Ghana, treadle pump users were able to grow multiple crops. In Zambia Treadle Pump users of were able to grow three crops a year.

Trends in revenues and profits after including additional costs of greening

For groundnut crops, analysis of profitability showed that both systems (wheat straw and wheat straw with plastic cover) have positive income returns of US$ 92/ha and US$ 42/ha respec- tively. For grain crops, long-term profitability is possible with the use of mulch depending on the costs of mulch.

Revenues and profits are likely to be positive and increase, except during very wet year.

Incomes for Treadle Pump users increased by more than 28 per cent in Ghana. On average users earned almost US$ 343/farmer over non-users in Ghana. In Zambia, incomes rose more than six- fold. Farmers earned US$ 125 with bucket irrigation on 0.25 ha of land to US$ 850-1,700.

Barren land became more productive in Nepal. In Zimbabwe no significant differences in yield were observed. Water use reduced by 35%.

Average yield increases estimated to be between 3-20%.

Table 4: Selected evidence on benefits and costs of water management strategies 56

In Nepal, women farmers earned an additional US$ 70 annually by selling surplus vegetables.

Maize yield increases translate into US$ 0.53 billion. The ratio of returns to investment is estimated to be between 7 and 11 times.