Webinar On Smart Farming Tech In Africa: Key Takeaways
Learn the key takeaways from the webinar on precision agriculture improving livelihoods and increasing yields in Africa, hosted jointly by EOS Data Analytics and Agroxchange Technology.
Planting cover crops is a common and rewarding farming practice that was applied as far back as in the Roman Empire. Since then, the method has been widely used in agriculture, bringing a lot of good. Farmers reap a plethora of cover crop benefits that fit versatile objectives, both in the short-term and long-term perspective.
Cover crops help prevent soil erosion, regulate moisture, attract pollinators, assist in weed and pest management, serve as mulch and the source of green manure and organic matter, and are used for grazing or forage. Depending on the types of cover crops, they add or uptake nitrogen.
As the name hints, these are plants to cover soils for certain reasons. Unlike primary species, they support secondary farmer’s needs rather than are grown for trade or human consumption. They improve soil health, boost yields, and feed the cattle. However, it does not mean that these plants are some exclusive species. In alternative situations, they serve as cash cultures, and you can find them on the plate as well (for example, buckwheat or corn). The difference is that in the case of fall cover crops, these species are used as grasses.
Farmers plant them in different seasons, either fall or late spring/summer, uniformly or between rows. Some are winter-killed, and some require removal and residue management. They also suggest one species at a time or their mixtures. The latter method is reported to bring more prolific results. Common cover crops are legumes, grasses (forage grains), brassicas, turnips, radishes, etc.
There are three main categories, depending on their properties and options for use: grasses, legumes, and broadleaf non-legumes. In most cases, they combine several functions at a time, like preventing erosion, improving soil quality, serving for grazing, among others.
Time to plant introduces another classification. Respectfully, agriculturalists distinguish fall, winter, spring, and summer types of cover crops. All of them have certain specifics in management, advantages and disadvantages.
These are mainly cereals planted after fall harvests of cash cultures. Their purpose is to serve as a natural ground “shield” until spring sows, not to bring yields. Basic requirements for their growth are enough warmth in the fall and sufficient moisture in the spring. They prevent soil erosion, combat weeds, conserve moisture, reduce leakage of nutrients but consume them as well. Also, their seeds require additional costs, may be hard to terminate, cause allelopathic effects, and interfere with primary culture development. Vegetation cover protects from diseases and pathogens, yet may produce quite the opposite results as well.
When planting cover agricultural species for winter, farmers should consider their resistance to frosts. Winter-hardy plants survive the harsh cold weather, while winter-killed ones are sensitive to considerable temperature drops and die during winter.
As the name suggests, this type grows in summer in-between primary species rotations. This practice is applied to defeat weeds, erosion, and adjust the earth for the next crop. Summer or spring cover crops also serve as fodder for livestock.
They prevent soil from quick drying with their roots compared to bare soils under the sunrays. Nevertheless, seeds may establish poorly in summer due to droughts and heat, induce nitrogen deficiency (unless these are legumes), require extra residue management, or longer time to decompose than expected, thus postponing the time for planting fall primary species.
As appears, the right time and correctly chosen agricultural cultures are the major keys to success, as benefits may easily turn into drawbacks when things go wrong. This is where Crop Monitoring can help farmers to face the challenge, using historical data to elaborate productivity maps. Via comparative analysis, you can choose the optimal time and agricultural species.
Farm owners can ripe additional benefits with cover crops for grazing cattle. Such species possess general advantages and are used as animal food as well. Furthermore, grazing cover crops enable farmers to create a natural outdoor environment for breeding, which is important in organic agriculture. Grazing also provides animal manure on pastures, saves expenses on livestock fodder, and facilitates removal before primary culture planting. This practice is especially rewarding in late fall, winter, and early spring due to a lack of fresh and juicy vegetation cover.
Typical cover crops for grazing are cereals and legumes like ryegrass, wheat, sorghum, millet, oats, triticale, barley, hairy vetch, red and white clover, pennisetum, lablab, Austrian winter pea, cowpea, alfalfa, fava among others.
Farmers plant cover crops to improve soil for certain reasons.
Roots of cover crops help prevent erosion from water and wind. Some species can adjust nutrients to more ingestible forms for other cultures. Planting cover crops between rows, farmers get mulch as part of integrated weed management. Furthermore, flowering inter-row species attract pollinators. Shallow and deep-rooted cover crops penetrate soil on alternative levels, tackling compaction, and enhancing aeration.
Its concentration rises with legumes and decreases with non-legumes. Legumes are known as nitrogen producing cover crops. Nevertheless, they do not catch and convert gaseous molecular nitrogen from the air by themselves.
Cover crops that fix nitrogen are symbiotic with the process mediators on their roots – the soil-dwelling rhizobia bacteria (formerly classified as agrobacterium). In their turn, the bacteria get carbohydrates from the legumes. The nutrient mostly releases when nitrogen-fixing cover crops or the bacteria die and decompose. Rhizobium also decreases root diseases in plants, but the group representative Rhizobium radiobacter induces infections in humans.
Another biological alternative to convert atmospheric nitrogen into soil one is performed by the non-symbiotic cyanobacteria family. Otherwise, nitrogen is reduced to plant-ingestible forms industrially in the process of chemical synthesis.
Cover crops can uptake excessive water after winter rainfall, enhance water infiltration (as well as soil aeration) with their roots, and retain moisture for the subsequent cash plants.
Crop Monitoring enables farmers to check soil moisture on two levels: on the upper surface (5 cm) and the root zone.
The choice of what culture to plant depends on its type and sequence. For example, legumes are beneficial for subsequent cash species for nitrogen supplies. Correspondingly, farmers should not seed them when nitrogen levels saturate.
A study calculated that nitrogen uptake in maize silage increased after Austrian winter peas and decreased after rye as much as 40 kg/ha in both cases, compared to fallow.
Another aspect to consider is the time required for proper cover plant decomposition. For example, buckwheat residue composts faster than barley or sorghum.
The all-in-one software by EOS provides a wide spectrum of vegetation indices that draw a comprehensive picture of plant development. For example, NDVI helps to check the general state of vegetation and distinguish the most critical areas (to spot the urge in irrigation or fertilizers, for example). MSAVI allows controlling seedlings as it is not prone to the soil background. NDRE monitors nitrogen content via chlorophyll activity and aids in fertilizer applications as well as detects plant degradation.
Crop Monitoring uses historical data on vegetation to elaborate productivity maps that allow agro specialists to reduce seeding and fertilizing costs. Retrieving information on phenological stages, farm owners can schedule field activities as certain operations like spraying and fertilizing must take place in a certain growth stage.
Past weather records give an opportunity to precipitate severe winters or summers. Weather forecasts enable farmers to efficiently schedule field activities like herbicide termination since some herbicides require dry weather, while others need rainfall to react.
Thus, the tool helps agriculturalists decide when to plant cover crops, how to treat them, and when to terminate them as well as record field operations with the activity log. Farmers can monitor the overall process of plant development, density, and health. Credible information promotes smart agro decisions and the team will assist in the software implementations.