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Project

PRECISION FERTILIZER: precision fertilization with animal manure (PRECISIEMEST)

Problem statement

After several manure action plans the Flemish manure problem remains urgent. The percentage of red MAP measurement points where the threshold limit of 50 mg nitrate per liter surface water was exceeded in the winter year 2015-2016 remained at 20%. The norm for phosphate was exceeded in 77% of the measurement points. In 2015, als 33% of the measurement points for freatic ground water exceeded the nitrate limits. So, additional efforts are required to bring the nitrate and phosphate levels in the ground and surfae waters, and the nitrate residues in the soil under control. To minimize their environmental impact and maximize their rendability, Flemish famers have to apply nutrients when and where they are beste used by the crop. 

While a lot of research had already been performed on the technology for site-specific fertimization, most farmers still apply a uniform dose per field. By merging historically separated parcels and local variation in soil texture, large yield variation can be observed within one field. In crops where a part of the nutrients are applied in the form of manure this variation is even more pronounced, because it is typically applied at a fixed volumetric rated based on a forfaitary or average composition while the manure composition can vary substantially from one load to the next. As these differences are often clearly visible during the growing season and at harvest, some farmers try to correct for this through variable rate application of the second fraction based on crop measurements. However, the translation of these crop measurements in a suitable fertilizer dose is not trivial. Without additional information on the soil condition a slower development of the crop may as well be interpreted as an argument for a higher or a lower dose.   

Opportunities and goals

After years of scientific research in Flanders and the neighboring countries, technologies for mapping the variation in soil fertility within a field and for manure application based on an online composition measurement have become commercially available. However, the added value for the farmer and the environment (e.g. nitrate residue) were not clear.  Therefore, the aim of this project was to investigate different practical scenarios and to provide the scientific arguments to convince famers to take the path of innovation towards precision fertilization.  

Approach

In this project different scenarios for precision fertilization with manure were tested and benchmarked aganst the common practice in terms of rendability (gains vs. costs) and environmental impact. While defining the scenarios two factors were considered for which the level of precision is varied: soil fertility and manure composition. For soil fertility two levels were compared: advice at field level and advice at the level of management zones defined based on online measurements of important soil parameters in combination with targeted soil sampling.  For manure composition, we either applied the manure based on the average composition (estimate or storage analysis) or based on an online measurement of the composition. To evaluate the added value of the different scenarios widely, they were tested for different soil textures (sand and loam) and crops (maize, grass and potatoes). In a first stage, this was done by the test stations (Hooibeekhoeve and Soil Service of Belgium), but in a second phase the scenarios were also tested on farmers' fields and compared to their current practice. 

To attract farmers to the path of precision agriculture a knowledge center was established that supports farmers in choosing, implementing and using precision agricultre technology on their farm. Through collaboration with existing initiatives such as the IBN Smart Digital Farming and the operational group SOCROSens this knowledge center brings technology providers closer to farmers and vice versa. Besides the technologies and scenarios elaborated in this project the platform also supports the selection and implementation of other sensors for precision agriculture. In this way, it makes precision technology more accessible for the Flemish farmer and stimulates innovation in the sector to increase the international competitiveness. To reach these goals the applicants exploit their expertise over the full spectrum from basic research (KU Leuven) to applied research (Soil Service of Belgium and Hooibeekhoeve). 

Date:1 Oct 2019 →  30 Sep 2023
Keywords:precision fertilization, animal manure, site-specific fertilization
Disciplines:Biotechnology for agricultural, forestry, fisheries and allied sciences not elsewhere classified, Sustainable agriculture