Good conservation management practices help accumulate carbon in the soil and can boost productivity

Changes in climate have caused countless losses to agriculture, whether due to the occurrence of long periods of drought or due to events with intense rainfall, causing soil erosion and reducing harvest potential. In adverse situations such as these, adequate soil management becomes even more important, as its purpose is to provide an adequate supply of air, water and nutrients for crops to develop and express their potential. In other words, this means that the roots, when occupying the soil pores, must have air, water and nutrients available at sufficient levels.

The search for soil management systems that harmonize the development of new technologies with economic viability, minimizing environmental impact and reducing greenhouse gas emissions, has been the challenge of rural producers and the scientific community in recent decades. Examples of conservation management systems include direct planting, a strategy that has proven to be efficient in mitigating atmospheric CO2 and accumulating carbon in the soil.

Direct planting is based on three pillars: planting without disturbing the soil (restricted to the sowing line), permanent soil coverage (with live plants or straw) and diversification of plants in the crop rotation. The importance of this system lies in the fact that it requires fewer soil management operations (such as less use of fossil fuels and fertilizers) than conventional tillage, all while sequestering organic carbon, a key component in controlling physical attributes, chemical and biological soil.

The first step for this management system to achieve a high level of efficiency in this strategy is to intensify the production system, aiming to close the windows between the rainy season and the dry period to keep the soil permanently covered. To achieve this, it is possible to use crops for soil cover - such as black oats, rye, vetch, lupins and forage peas for the southern region, as well as millet, brachiaria, forage sorghum, sunn hemp, pigeon peas, stylosanthes for the tropical region and cerrados. , in combination with commercial crops.

Additionally, managing acidity with liming, the use of gypsum to increase the calcium content and the adequacy of fertilization (NPK and micronutrients) will contribute to increasing crop yields and the accumulation of C in the soil. This is the purpose of relevant ongoing initiatives on the topic, such as Carbono Bayer, developed in partnership with the Brazilian Federation of the Direct Planting System.

João Carlos de Moraes Sá, retired senior professor at UEPG (State University of Ponta Grossa), CNPq Research Productivity Fellow - Level 1D and president of the Technical-Scientific Commission - FEBRAPDP (Brazilian Federation of the Direct Planting System)