Does Digestate Dose Affect Fodder Security and Nutritive Value?

Abstract

With the rising interest in digestate use as a fertilizer on permanent cultures, there is a need to examine its effects on food and feed quality. This study is focused on the use of digestate in grassland fertilization and its effects on nutritive value parameters such as mycotoxin contamination (deoxynivalenol, aflatoxin, and T-2 toxin) and nutrient content (crude protein, crude fat, crude fiber, ash, nitrogen-free extract, digestibility of organic matter, acid detergent fiber, and ash-free neutral detergent fiber). The experiment was carried out in the Czech Republic, and the effects of fertilization regime, year, and harvest date (summer and fall cuts) on nutritive value were observed. An effect of the year on DON, AFB1, and T-2 contamination levels was observed. An effect of the harvest or fertilization regime on mycotoxin contamination was not observed. Significant differences were observed in the content of all nutrients, except ash, depending on the year. Differences were found only in the case of ADF levels, depending on the harvest date, as well; however, no differences were found between fertilization regimes. Our findings suggest that digestate does not negatively affect fodder in terms of nutritive value nor safety.

Digestate Application Methods and Rates with Regard to Greenhouse Gas Emissions and Crop Conditions

“…The digestate rates focused on in this analysis showed an increase in the oilseed rape yield depending on the dose applied [19]. Another study [20] verified that digestate can be used as a fertilizer on grasslands with no significant effect on the nutritive value, and that fodder safety will not be compromised by digestate fertilization in repetitive higher doses of 40 m 3 ha −1 . Digestate can partially replace the use of mineral fertilizers.…”

Effect of Mycotoxins in Silage on Biogas Production

“…It is also necessary to realize that silage AD gives rise not only to biogas but also to fermentation residues in the form of digestate, which can be contaminated by mycotoxins too [28]. Additionally, when digestate is used as fertilizer, it is necessary to investigate its influence on the quality of food and feed products not only in terms of nutritional value [29], but also in terms of soil properties [30,31], as well as the possible contamination of the environment with mycotoxins [32]. This study presents a novel combined evaluation of the content of mycotoxins in the contaminated silage, their effect on biogas and methane production, and the degradation of mycotoxins during the AD process (monitored as the residual content of mycotoxins in the digestate).…”

“…It is also necessary to realize that silage AD gives rise not only to biogas but also to fermentation residues in the form of digestate, which can be contaminated by mycotoxins too [28]. Additionally, when digestate is used as fertilizer, it is necessary to investigate its influence on the quality of food and feed products not only in terms of nutritional value [29], but also in terms of soil properties [30,31], as well as the possible contamination of the environment with mycotoxins [32].…”