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Cropping systems
Photo: ICRISAT
Bounty chickpea harvest in Ethiopia. Drought-tolerant crops are essential for food security.
 
 

Growing crops in the drylands is a risky enterprise for millions of small farms, a business that yields poorly. The crop choice depends on each household’s objectives, resources and environment. Many agricultural innovations could significantly raise the productivity of these cropping systems.

7 - Neolithic founder crops found in the fertile crescent: 3 cereals and 4 legumes (Lev-Yadun 2000)

50,000 - potential edible plants

60% – of the world's food energy intake comes from rice, maize and wheat

40%  – increase in demand for dryland cereals expected by year 2020 compared to 2000 in sub Saharan Africa and South Asia (IFPRI)

46 million tons – of nitrogen fixed biologically by legumes compared to 87 million tons of nitrogen fertilizer used each year (Peoples and al 2009)

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Understanding the crop enterprise in a smallholder farm

A cropping system is a combination of plants cultivated/managed by a farmer, over time and farm space, for specific purposes including grain, fodder, fibre, oil or other raw material, income and/or ecosystem services (eg soil cover to fight soil erosion). 

The cropping system is defined in terms of rainy seasons (eg called kharif in India) and post-rainy crop seasons (called rabi in India). Farmer priorities will depend on which season farmers are planting their crop in. For instance, the 5 million farmers growing rabi sorghum in India need to be able to manage drought conditions.  Farmers will also manage their crop portfolio according to optimum farmland use (eg high value crops on best soils).

Integrated - the choice of crops depend on various interactions with the soil, water and farm resources, other farm/household enterprises, and the external environment (eg agricultural policies, agroecological conditions like rainfall, temperature and other factors influencing plant growth, technology and social environment).

Crop utilization patterns are different for each crop and each region. For instance, about half the pearl millet produced in Western India in 2011 was used as grain, 40% as animal feed and around 10% for beverage transformation.

Crop use may also change from one farm to another depending on their overall farming system. Food feed crops will be interesting for mixed crop-livestock farming systems. Farmer and Market preferences influence this crop choice.

Farmer participatory research, eg participatory variety selection (PVS), is important for crop adoption.

ICRISAT's research looks at two complementary approaches:

  • Reducing vulnerability, increasing resilience and mitigating risk from biophysical and socioeconomic shocks despite marginal conditions; and
  • Sustainable intensification of production systems to improve livelihoods.

Better crop management strategies to boost the productivity of smallholder cropping systems

For most smallholder farmers in the semi-arid tropics, growing crops is challenging because of many dryland stresses and access to quality inputs, irrigation and other technologies is poor. Yields are low and the risk of losing crops due to drought and other climate incidents is high.

Crop management comprises of a series of farming operations to overcome the dryland stresses affecting plant growth and achieve the highest yield and/or crop net value, including :

  • Soil preparation [eg techniques such as the broad bed and furrow tilling or zai pits increase water conservation and yields under drought conditions]
  • Soil fertility / nutrient management. ICRISAT looks at fertilizing techniques adapted to poor smallholder farmers. A recent study in Jharkhand, India showed that a balanced plant nutrition in nitrogen, phosphorus and potassium (macro-nutrients) as well as small tailored quantities of  micronutrients like boron or zinc increased crop yields by up to 56%. This success can also be seen with Bhoo Chetana's approach to boost yield through optimum micronutrient management.  Fertilizer microdosing (applying a bottle cap of fertilizer at the plant roots) is promoted in sub-saharan Africa where access to fertilizer is limited and this has seen significant impacts in yield. Vermicomposting and other natural ways also improve soil health
  • Choice of crop portfolio and seed systems. Dryland smallholder farms do not usually use quality seeds of high-yield, pest-resistant and climate smart varieties available through formal seed systems. ICRISAT is studying ways to increase adoption of improved varieties of dryland cereals and grain legumes [see in particular Hope ; Tropical Legumes 2]
  • Water management: Our watershed research improves water conservation for rainfed agriculture. Small-scale irrigation systems are also very effective in increasing productivity for dryland farmers. Eg The African Market Garden, a 500 m² drip irrigated vegetable system developed together with the World Vegetable Center
  • Pest and weed management. Legumes in particular are prone to pest attacks. More than 50 chickpea diseases have been reported in India in particular soil-borne diseases like Fusarium wilt, calling for adapted seed treatment practices. Pod borer (Helicoverpa armigera) has caused chickpea yield losses of over $328 million in the semi-arid tropics. Understanding the plant mechanisms for pest resistance and climate influence on pest attacks is essential.  ICRISAT has developed an integrated striga control pack to fight this parasitic weed which proliferates in sub Saharan Africa in poor soils of dryland cereal monocropping systems. Striga causes up to 40 to 80% yield losses in sorghum and millet fields.
  • Harvesting and post-harvesting operations to reduce crop losses.

What crop management actions are needed for coping with drought and adapting to climate change in the drylands? Crop simulation models have been used to understand Genotype x Environment x Management interactions, and more recently to examine impacts of climate change on crop yields.

Crop diversification, both through crop rotation or intercropping, avoids unsustainable nutrient mining and achieves better productivity. In Gujarat, the rice - fenugreek - okra system productivity was more than three time higher than the traditional rice-wheat-fallow system. Grain legumes should play a greater role in future smallholder crop systems given their ability to enhance nitrogen and phosphorus levels in cropping systems. Agroforestry systems mixing annual crops and drought-tolerant trees can be a resilient and productive cropping system in harsh, dry climate.

"Integrated striga control pack" to eradicate striga weed in sorghum and millet fields.
Photo: ICRISAT
Pearl millet threshing in Niger – dryland cereals like millets and sorghum are essential for dryland cropping systems but often suffer low productivity.
Photo: ICRISAT
Groundnut frying in Mali - The choice of strategies to improve crop systems with input access, crop processing and markets depend on local farmer preferences
Photo: ICRISAT
Appropriate fertilization techniques like microdosing boost yields.
Photo: ICRISAT
Better access to improved seeds is a cost-effective way to increase crop productivity in small farms in drylands . Here a chickpea seed producer in Ethiopia (Tropical Legumes 2).
Photo: ICRISAT
Helicoverpa larvae on chickpea foliage, a devastating pest for dryland legume farmers.

Maize – pigeonpea intercropping in Tanzania (SIMLESA project with CIMMYT).

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