from our newsletter, broadcast on
Wednesday July 30, 2014
The loss of soil quality is becoming a worldwide phenomenon. Deforestation, land degradation and desertification are just some of the problems facing farmers today, threatening agriculture, the environment, and food security. According to the USDA, the productivity of some lands has declined by 50% due to soil erosion and desertification, costing the U.S. about $44 billion per year. Globally, the annual loss of 75 billion tons of soil costs the world approximately $400 billion per year.
There are various projects that will address soil restoration as a key attribute, and one in particular offers great opportunities. Perennial grain crops, crops with the potential to be used as multi-purpose crops, are currently being tested in various countries in Africa by researchers at Michigan State University (MSU) thanks to a $1.49-million grant from the Bill and Melinda Gates Foundation under the direction of Dr. Sieglinde Snapp, Professor, Soils and Cropping Systems Ecologist. The new project is assessing the possibility of these grains to be grown in a perennial system, initialing identifying the potential risks and benefits of two perennial grains; perennial sorghum and perennial pigeon pea. This work spans five Africa countries, including Ghana, Mali, Malawi, Tanzania and Ethiopia.
Perennial plants are different from annual plants in that they live in the soil year round. They may not be growing in the winter but as soon as the soil warms a bit they start growing, and during the winter the roots serve as a blockade to hold the soil in place. This reduces soil erosion and nutrient leaching. Also, a perennial crop is planted once every few years versus every year as in the case of an annual crop. In addition, the perennial cropping system requires fewer times driving on the soil with the tractor or labor of hand planting, so there is less tractor time, less labor, and less seed cost for planting.
Vicki Morrone, MS, is an organic field crop and vegetable outreach specialist at MSU, participating in a perennial wheat research project. She says that plant breeders developed this grain through traditional breeding, crossing annual wheat and perennial grasses. Perennial grains typically have three to five times as many roots as annual grains, living several years, and these roots provide the nutrients and water it needs for multiple years – a real advantage of growing perennials over annual crops. Since roots live in the soil and not on the surface, they are there holding on to soil and physically supporting the plant. They also hold the soil particles in place, keeping them from washing away in a rainstorm, thus reducing erosion.
“Roots are the answer,” says Morrone. “The more roots per plant the more soil is held. Roots take up moisture or water to feed the plant, the same water that contains nutrients, which can be regarded as pollution if leaked into ground water or our waterways. Having plants growing all year reduces compaction and improves water infiltration for gains in water conservation. A plant growing for 10 months of the year or so also captures twice as much sunlight and provides multiple benefits: production of forage, grain and soil conservation.”
While the advantages are clear, there are some real challenges to rolling out perennial grains, says Morrone, because the economics are simply not there when considering how to replace annual grains in our food system. Perennials are a longer commitment in terms of space, time and land. If you rent land, for example, you may not want to invest in a perennial crop. And growing perennial crops using organic practices is tough since there are really no effective herbicides (to kill the weeds) that are also allowed in organic production. The organic farmer is then dependent on reducing weeds through regular tillage. Another roadblock is the fact that our food system is heavily dependent on grains and fruits which generally are annuals, and that is because annuals generally have a greater yearly yield.
“Grain quality may be there for perennials, especially in terms of micro-nutrients, but the amount a farmer is paid for the harvest is not based on the nutrients of the grain but on the weight, thus the focus for crop selection in the past has been greatly on high yields and large seeds. Who pays the farmer for doing a good job to reduce erosion?” says Morrone.
If a sound economic model is developed that regards both environmental and agronomic attributes, says Morrone, then perennials stand a chance in our food production system. The potential benefits are huge, from improving soil nutrients to improving soil health. These types of improvements can better support a crop for more than one year. However, perennial grain like other perennials produces smaller seeds (compared to annuals) and may or may not produce ‘a good crop of seed’ in a given year if conditions are not favorable. Therefore regarding the perennial grains merely for their production of seed is short-sighted.
There still needs to be development of improved perennial grains, and plant breeders need to be supported to develop crops such as perennial wheat, perennial sorghum and perennial peas. Perennial corn is a long way off, but other crops are showing promise.
Six months into the Gates Foundation-funded project, Snapp says they are excited about their progress. For the first time novel perennial sorghum crops have been planted in West Africa and have started to grow, and the research team is eagerly awaiting assessing their performance through close monitoring. They are growing perennials on research stations across a transect of ecological zones, on both marginal and fertile soils, to observe them before they are made available more widely.
“At the same time, we have been conducting intensive bibliography reviews and have found historical records of a type of perennial sorghum that was grown in Southern Africa (Malawi, Zambia and Tanzania) in the 1940s. Follow up will include literature databases to allow broad access by the public to information we collect and synthesize on perennial grains, and semi-perennial grains such as the pigeon pea,” says Snapp.
Additionally, Snapp says that they have recently initiated consultation with experts and local farmers in Mali (West Africa) and in Malawi (Southern Africa) and are exploring through mapping, and focused discussions, as well as through community scenario visioning, the types of transformative agriculture that might address the future needs of smallholder farmers. They are particularly excited about the drought tolerance potential of perennial grains to provide options for farmers affected by climate change.