FAEP/SENAR-PR System Seminars reinforce soil conservation

In August 2022, the FAEP/SENAR-PR System promoted the Soil Conservation Seminar in seven cities in Paraná, addressing several related topics. The focus was to regionalize the discussions and bring topics relevant to the regions. Among the countless ways to conserve the soil, the use of terraces and the direct planting system are the ones most remembered by producers. But there are others that reflect profit within the property. The main message conveyed at the events was that soil conservation is not synonymous with loss, as many associate it with non-cultivation. It is precisely the opposite, as agricultural cultivation is a form of soil conservation.

Researcher Tiago Telles, from IDR-Londrina, presented three cultivation systems that most represent Paraná: Succession system – soybeans in the summer and corn in the winter; Rotation I – three-year evaluation, with soybeans/corn/soybeans in the summer and rye + black oats in the winter in the 1st year; white oat + turnip in the 2nd year and brachiaria in the 3rd year; Rotation II – corn + brachiaria/corn + brachiaria/soybean in summer and wheat in winter in the 1st year; canola in the 2nd year and beans in the 3rd year.

Comparing rotation systems with the crop succession system, the profit can be R$826 more in the former. This is because, although succession is two commercial crops, rotation systems keep the soil covered with the greatest diversity of plants, reducing production costs (fertilizers, herbicides, etc.) and increasing productivity, as there is less erosion. The rotation allows the harvesting of grains in the winter (wheat, beans and canola), as in the summer the intercropping with brachiaria maintains straw in the soil and ensures nutrient cycling. The producer's greatest profit, in most cases, is not associated with the system based only on commercial crops, but with those with greater plant diversity in the soil.

Conserved soil allows the producer to sell the land for higher prices. According to data from the IBGE Agricultural Census, the highest sales values ​​were in areas under direct planting, that is, with more preserved soil. This is because whoever buys the area will spend less to produce. Soils under direct planting are worth almost R$11 per hectare more than areas under minimum tillage (where “light harrowing” or scarification occurs, with soil compaction, less water infiltration, greater erosion and consequently higher production costs) . As the soil is an asset of the rural producer, conservation allows adding value to the land.

Keeping the soil vegetated, without disturbance, was the watchword of the more than 40 researchers who spoke at the event. The absence of disturbance keeps the roots of the previous crop in the soil. For example, soybean productivity in soils under winter fallow in Londrina in the 2017/18 harvest was 38 bags per hectare, while in soils with Piatã as cover in winter it was 67 bags per hectare, under the same climate and fertilization conditions. . At the time, more than 70% of the mass of Piatã kept in the soil was “below the surface”, that is, the roots. This means that their maintenance is extremely important for productivity. Remembering that the focus also needs to be on increasing production and reducing costs, aiming for greater profit.

Straw in the soil (roots and area) favors the nutrient cycling process. In the 2021/22 harvest, producers were surprised by the spike in fertilizer prices. At the time, those who kept the soil preserved had lower input costs, as plants are pumps that bring, through their roots, nutrients from deeper layers to the surface. Furthermore, with the decomposition of straw, these elements, lost in previous harvests, are released into the current agricultural culture. The degradation of straw from cover crops must be slow and gradual, providing organic matter to the soil, which will be the source of nutrients for the next crops, reducing fertilizer costs.

Another way to supply organic matter to the soil is to use animal waste as fertilizer, something widely discussed in the western region of Paraná. This process is a form of soil conservation.

Soil conservation should be seen by producers as a long-term action to conserve agricultural heritage and reduce costs. Increasing productivity must always be combined with reducing costs and increasing profits, as this alone is an ineffective action. Soil conservation is the most effective way to increase profits and preserve rural producers' assets, as it adds value to the land, produces more and reduces expenses and environmental impacts.