Rational use of waste in fertilization generates savings

The use of animal waste as fertilizer is an alternative known to many rural producers. In addition to improving soil properties, organic fertilizer has proven to be a viable option to replace mineral fertilizers, reducing production costs and making the agricultural system even more sustainable. Despite its effectiveness, the application of waste requires monitoring, as indiscriminate use can cause reverse effects and result in environmental problems, such as contamination of water resources.

It is in this context that the subproject “Hydrosedimentological monitoring in microplots with application of animal waste in Southwest Paraná” is being developed, which is part of the AgroResearch and Applied Training Network Paraná (Rede AgroParaná), an initiative that has financial support from SENAR -PR and the state government. The objective is to evaluate the effect of the use of waste on crop productivity and losses of soil, water and nutrients through surface runoff in areas of the Direct Planting System (SPD), on the Dois Vizinhos campus of the Federal Technological University of Paraná (UTFPR ).

“Paraná is one of the states that generates the most waste, considering that it is the largest producer of animal protein in Brazil. Producers already apply waste on a large scale. The problem is that they often use doses higher than recommended. With this monitoring, it will be possible to guide management and reduce environmental impacts”, explains Carlos Alberto Casali, professor at UTFPR and responsible for the subproject.

For this study, in addition to Rede AgroParaná, partnerships were signed with Embrapa Swine and Poultry, Frimesa cooperative, Institute of Rural Development of Paraná (IDR-Paraná) and Center for Agroveterinary Sciences (CAV) of the State University of Santa Catarina (Udesc -Lages).

In the area, metal gutters were installed with three treatments: without fertilization; mineral fertilizer in the line; and broadcast mineral fertilizer, pig and cattle manure and poultry litter. Since 2019, in the months of May and October, treatments have been applied to soybean and wheat crops.

In crops, the mass productivity of the dry matter of the aerial part and grains is evaluated, in addition to the yield components. With soil sampling from the surface layer (up to 10 centimeters), chemical and microbiological parameters are also measured. From the runoff samples, the volume and quantity of sediments and nutrients are evaluated, in addition to chemical characterization.

Preliminary results

So far, the research results indicate that there has been less surface runoff in places where animal waste is applied. The increase in the production of dry matter from the aerial part generated greater addition of residues in the plots, which can also alleviate the erosion process.

In 25% of the collections carried out so far, it was found that the use of waste reduced the loss of volume of soil and water runoff, which may be related to the increase in the production of plant biomass, reducing soil erosive processes and resulting in greater crop productivity.

In relation to productivity levels in the period analyzed so far, one wheat and two soybean crops had similar results, whether with organic or mineral fertilization. A soybean crop with the application of organic fertilizers had 15% more productivity compared to the use of minerals.

“The fact of having the same productivity is already extremely positive. This shows the potential of animal waste to reduce or even completely replace mineral fertilizers, without compromising the results of agricultural production. In addition to recycling an environmental liability, the producer can also reduce costs, even more so if we consider the current prices of mineral fertilizers”, concludes Casali.