Diversiﬁcation strategies in millet production

There are many ways to diversify a millet cropping system. It can be achieved through growing different millet species or varieties, or growing millet together with other crops – in rotations or in mixtures.

Varietal diversiﬁcation

Millet has a wide range of maturity periods. Some varieties mature in as little as 60 to 80 days (short duration) while others take about 100 days (medium) to mature. Long season varieties can take up to 180 days to mature from planting. Cultivation of short-duration varieties reduces the risk of crop failure. In areas with two rainy seasons, millet can be grown during the short rains. Where rainfall is sufﬁcient, double cropping is possible after short-duration millet.

Mixed cropping

In traditional cropping systems, millet is mostly grown together with other crops. The reason lies in the numerous advantages associated with mixed cropping such as higher total and safer yields, better use of the resources, and cultural advantages such as better weed control and soil protection. In West Africa, pearl millet is often intercropped with other cereals like other millets or sorghum, or with legumes like cowpea or groundnut. Intercropping patterns vary depending on rainfall regime and other factors such as crop preferences. Intercropped legume and millet are usually sown in alternating rows. In the case of cowpea, growing two rows of millet and four rows of cowpea has proved more productive than alternating single rows of both crops. Sowing times, varieties and cropping patterns should be chosen in a way that avoids competition by the legume for water, nutrients and light. Cowpea may be sown two to four weeks after millet. Longer growing seasons offer greater possibilities of adapting the system. Intercropping of millet with a drought-tolerant legume in general increases productivity of both crops compared to cultivation of a sole crop.

Cultivation of nitrogen ﬁxing trees in rows increases the diversity of the cropping system, while offering additional, highly nutritional forage for livestock, enriching and protecting the topsoil with the fallen leaves in the wet season, ﬁxing nitrogen on its roots and drawing nutrients from deep soil layers. All these effects contribute to improvement of yields of millet. Although millet prefers unshaded conditions, it will proﬁt from improved nitrogen supply and soil conditions in proximity of the trees. Drought stress, phosphorus deﬁciency, and increased bird damage (harboured by the trees) may though limit advantages of diversiﬁcation of the farming system with trees.

Discussion on diversiﬁcation strategies in millet production

Ask the farmers, if they know any other (indigenous) methods to enhance yields and reduce losses of millet. Let them identify any other practices which they think can contribute to increased and better production of millet. Guide the selection of appropriate practices based on local applicability and affordability

Crop rotation

Pearl millet grows well after a legume or root crop. Rotation of millet with legumes allows growing the legume at higher density than it is possible in an intercropping system. Depending on the species, their nitrogen ﬁxation rate and their use (feed for livestock, incorporation into the soil as green manure, grains for human consumption), legume crops grown prior to millet will have a more or less positive impact on the yield of the following millet crop. Rotation (and to a smaller extent intercropping) of millet with legumes furthermore reduces infestation of the parasitic weed Striga, an economic weed for millet. Rotation of millet with fallow, which is another possibility of diversiﬁcation that is traditionally used, does also contribute to better growth of millet, but in general does not substantially improve soil fertility, and regeneration of soil fertility is slower under natural fallow.

For more information on crop rotation see section on soil fertility management.

Discussion on crops for rotation and mixed cropping and mixed cropping

Find out, if farmers practice planned rotations. Determine and evaluate together with them suitable crops for rotation or mixed cropping. Estimate potentials and constraints of the different combinations.

Using millet as feed for livestock

Basically, organic agriculture encourages the introduction of livestock into the farming system, as they transform plant biomass into animal products and provide manure for the crops. But where land is short and plant growth is limited due to scarce rains, there may be need to renounce to the introduction of livestock, or there may be need to remove livestock from the farming system to avoid competition to human food production and provide more biomass for soil fertility management. It may be more efﬁcient to farm less land applying proper soil fertility management without using animal traction, than to manage a larger area poorly. If the stubbles, tree leaves and other plant materials are grazed by livestock, biomass will not be available for soil fertility management and the soil is left more or less bare through the dry season - creating unfavourable conditions for improvement of soil fertility. If the farm is managed without livestock, surplus grain legumes may be substituted for some livestock products and increased planting of a wider variety of legumes would improve the sustainability of the cropping system.

Where conditions allow, pearl millet can be grown for livestock feed where animals with high nutrient requirements such as growing animals, lactating dairy cows, or calves are allowed to graze on the growing crop. In this case, the pearl millet can be used either under a continuous or a rotational grazing system. For most efﬁcient use of the pearl millet, animals can be turned into pastures when pearl millet has reached a height of about 50 to slightly over 60 cm. The animals can be allowed to continue grazing until the pearl millet plants have been reduced to about 15 to 20 cm height. Overgrazing must be avoided, if the pearl millet is to be allowed to regenerate for the next rotational grazing phase.

Besides grazing, the pearl millet can be processed into hay and silage. Due to the thick pearl millet stems, the curing time in hay production is longer than with other hay crops, but the curing time can be reduced by crushing the stems, if facilities are available. The best times to cut the millet are: ﬁrst cutting at 60 to 65 days after planting when the plants are about 90 cm tall; thereafter at intervals of 30 to 35 days. For making silage, the pearl millet should be cut at boot to soft dough stage as this gives an optimal nutritive value to the silage. The plants should be wilted before chopping for storage.