Making mulch and fodder while sunn hemp shines

    By Busani Bafana

    Retaining maize residues for mulching or feeding to cattle is a difficult decision smallholder farmers in Zimbabwe have to make each harvest season.

    One farmer, Simon Madhovi from Madhovi village, ward 28 of Murewa District has found a win-win solution by mulching his field with residues from sunn hemp (Crotalaria juncea), a nitrogen fixing leguminous crop he intercrops with maize. Sunn hemp is a fast growing cover crop which has been found to improve soil fertility, enhance crop yields and make nutritive feed for livestock.

    Agriculture researchers are promoting hardy purpose crops such as sunn hemp to help livestock and crop farmers cope with droughts which have affected crop and livestock production. In Zimbabwe, smallholder farmers suffer low yields as a result of poor soils and the productivity of their livestock is affected by poor feeding as a result of persistent drought conditions.

    Sunn hemp has been introduced as a mulch and fodder crop to smallholder farmers in Goromonzi, Murewa, Mutoko and Uzumba districts of Mashonaland East Province under the Zimbabwe Crop-Livestock Integration for Food Security (ZimCLIFS) project led by the International Livestock Research Institute (ILRI) and International Maize and Wheat Improvement Center (CIMMYT) in partnership with Community Technology Development Organization (CTDO), Cluster Agricultural Development Services (CADS) and the government departments. The project funded by Australian Centre for International Agricultural Research aims to improve livelihoods, through increasing food production and food security, enhanced through the adoption of sustainable crop and livestock management practices such as conservation agriculture (CA).

    Under mixed crop-livestock systems, maize residues are often needed for feeding livestock during the dry winter months and for mulching the soil when practicing CA techniques which involve providing at least 30% permanent soil cover using live or dead mulches, crop rotation and reduced soil disturbance.  Due to the low maize yields often generated by farmers in semi-arid areas and the need to feed animals which communally grazed arable fields during winter, farmers often find themselves failing to protect and increase the fertility of their soils leading to poor yields.

    Mulching using sun hemp helped Madhowi reduce labour in having to cut grass and collect leaves which has used for soil cover before he was introduced to the legume crop.

    “Sunn hemp has helped improve our poor soils and allowed me to feed my maize residues to cattle while I mulch my field using sunn hemp residues,” said Madhovi, who also grows forage legumes such as mucuna, lablab, cowpea and groundnuts in rotation with maize to replenish soil fertility and pen feed his livestock. He observed double crop yields under CA compared to conventionally tilled fields.

    After pen fattening, Madhovi’s livestock improved and have been able to draw a ripper marking planting furrows in preparing his fields for the next cropping season. He sold one cow for $900 and bought three more cows and used part of the income for school fees, groceries and agricultural inputs for the next season.

    CIMMYT agronomists provided new legume seeds to farmers at the start of the project and have been involved in farmer training on conservation agriculture and use of equipment use, input use and best farming practices. ILRI researchers have trained the farmers on harvesting legumes for hay, making livestock feed formulation and storing hay.

    The training made a difference because the farmers have adopted CA practices and fodder production principles, says Eleanor Magwaza, a Research Associate and Agronomist at CIMMYT.

    “The farmers’ ability to continue after the ZIMCLIFS project withdrew from the area showed they appreciated the new interventions. The improvement in soil fertility, crop yields and availability of dry season winter feed resulting in higher household income and improved livelihood shows impact.’

    Magwaza said changing farmers’ mindset on the availability of markets for their crops and livestock were a challenge in getting the farmers to adopt sunn hemp. The project assisted in identifying markets for   grains and livestock through innovation platforms, formal platform bring together farmers, extension workers, researchers, traders and buyers to share knowledge in agriculture development.  In anticipation of technical challenges, extension workers and implementing partners were trained on use of equipment and herbicides to assist farmers.

    “Growing fodder crops and mulch is the way to go for farmers doing mixed crop-livestock production,” said Magwaza, adding that, “Competition for resources is reduced yet both crop and livestock production is increased. It is also a way of climate change adaptation and mitigation.”

    Other livestock non -palatable legumes such as tephrosia and grahamiana can also be planted in place of sunn hemp as these persist throughout the dry season and are chopped down to form mulch at the beginning of the next season, Magwaza said.

    There is need for increased targeted investment in enhancing the competitiveness of smallholder farmers to realize multiple benefits from livestock production by understanding the importance of feed and health for their animals, says livestock scientist and ILRI Southern Africa region representative, Sikhalazo Dube.

    “Farmers need to strike the right balance in livestock and crop production by understanding that livestock just like soils need to be healthy to be productive,” said Dube. “In this regard the integrated crop and livestock technologies such as the growing and use of legume fodder crops is critical given the rising demand for livestock products and the significant contribution of livestock to the economy.”