Autumn-winter crops

In the central region of Brazil, which encompasses the states of Mato Grosso do Sul, Mato Grosso, Goiás and Distrito Federal, in the spring-summer period, soybeans are the main cultivated species, with the state of Mato Grosso leading the cultivated area and the production. In addition to soybeans, corn and cotton are grown in a significantly smaller area. In the autumn-winter period, corn crops occupy the largest area. In Mato Grosso, in addition to corn, cotton is predominantly cultivated in succession to soybeans. In all states in the region, sorghum, sunflower, millet, brachiaria and beans are also cultivated, mainly, but the predominance is the soybean-corn monoculture, which from an agronomic point of view, when thinking about the sustainability of the system, is not the best alternative.

Both soybeans and corn, thanks to genetic improvement work, have become more efficient in grain production, to the detriment of the vegetative part, that is, they leave little crop residue after harvest on the soil surface. From an economic point of view, corn cultivation has become very interesting, due to the growing demand from both the domestic and foreign markets. Corn is the main component of poultry, pig and cattle feed, as well as being a raw material for ethanol production. It is also an excellent alternative for crop rotation. This already happens. Only part of the area is planted with corn. Increasing the supply of corn produced in the summer to meet growing demand may be an alternative from a sustainability point of view.

The adoption of good agricultural practices is considered one of the most viable strategies for adding resilience to the production system and reducing exposure to climate risks, also making it possible to reduce current production and productivity gaps. When we think about the sustainability of the system, some aspects cannot be neglected, such as: crop rotation, in the same area, in the same period of the year; use different species, both in spring-summer and autumn-winter; contribute plant material to the system, both on the soil surface and along the profile.

On the surface, the contribution occurs through the straw produced by the aerial part and along the profile through the roots. The roots are true and efficient subsoilers/scarifiers, without moving the soil. By not disturbing the soil and providing adequate straw, the soil begins to play a leading role in mitigating CO2, which is one of the gases responsible for global warming. From the perspective of diversifying production systems, a very interesting alternative is the cultivation of so-called winter plants; wheat and oats especially. These, as components of a production system, are important in generating income and can contribute to increasing the productivity of summer crops and reducing production costs.

It is worth noting that wheat is one of the only agricultural products that, to meet domestic consumption, Brazil imports, annually, around 50% of what it consumes. Several studies developed in different grain producing regions in Brazil demonstrate that the best weed management in summer crops depends on how the area was managed in the autumn-winter period. Especially for species that are difficult to control, such as bittergrass and horseweed, autumn/winter plants play a preponderant role, greatly facilitating the management of these species. Thus, the cultivation of corn + brachiaria, wheat and oats constitutes an important strategy when thinking about weed management.

Several other species can be cultivated as cover crops in the autumn-winter period, alone or in combination, such as sunn hemp, pigeon pea, stylozantes, millet, sudan grass, forage turnip, among others. This reduces summer crop production costs, especially with less use of herbicides and reduction in nematode populations, in addition to improving the physical, chemical and biological attributes of the soil. There are several alternatives when thinking about species to be cultivated in the autumn-winter period. Recent studies developed by Embrapa Swine and Poultry, for example, indicate the possibility of using wheat and oat grains in poultry and swine feed, thus increasing the possibilities of using autumn/winter plants.

This alternative represents another possibility of generating income for rural producers when they opt for cultivation in the autumn-winter period, in addition to the excellent opportunity to diversify the agricultural production system, currently very focused on soybean-corn cultivation. Diversifying and intensifying production systems is the great way to improve physical productivity, control of weeds and nematodes, thus reducing production costs and improving profitability. In all aspects, the cultivation of plants in the autumn-winter, in a planned and organized way, represents an excellent alternative for the farmer in the central region of Brazil.

Fernando Mendes Lamas (Researcher), Embrapa Agropecuária Oeste