The effects of innovative digestate and wood ash mixtures fertilizer on potato productivity

Field trials with the potato variety ‘Rigonda’ were carried out in sod stagnogley soil (56 ° 66 'N, 23 ° 75' E). Soil agrochemical parameters: pHKCl 6.7 organic matter (OV) content in soil 2.3%, phosphorus (P2O5) content – 149 mg kgE−1 and potassium (K2O) content – 200 mg kgE−1 in soil. Potato plantations were created using different variants of fertilizer mix with pig (from SIA “Latvi Dan Agro”) and cattle (from SIA “Ziedi JP”) manure digestate and wood ash (from SIA“Gren Jelgava”) of different ratio (digestate: wood ash ratio used: 4:1 and 3:1). The rates of innovative mixed fertilizer for pig and cattle manure digestates for potatoes were 15 and 30 t haE–1. Both norms for digestate manure from pure pigs and cattle were used as control options. The potato production norm was 3.0 t haE–1. The placement of the variants in the trial was randomized, in triplicate. In the study, the two types of fertilizer had different effects on potato tuber yield. Using mixtures of pig manure digestate and wood ash in different ratios, the average yield was 24.92 t haE–1, but using mixtures of bovine manure digestate and wood ash, the average yield was 22.78 t haE–1. The dry matter and crude protein content is the most ecologically sustainable indicator in potato tubers. The crude protein content of tubers determines the nutritional value of potatoes. In the studied variants, its content in potato dry matter varied in the range of 8.28–10.94%. The amount of dry matter affects the culinary properties of the tubers. The application of fertilizer mixtures increased the dry matter content by an average of 1.4–2.0%, reaching an average of 21%. Starch is the main ingredient in potatoes. Fertilizer variants with higher tuber yield or higher starch content provided the highest starch yield. In our studies, the average starch content in the dry matter was 73.3% and 15.3% in the natural product, but the average starch yield was 3.55 t haE–1. In general, the use of mixtures of wood ash and biogas digestate to fertilize crops and improve soil fertility can be an efficient way to process both products and can be an environmentally friendly alternative to fertilizers. The objective of the research was to study the influence of digestate and wood ash mixtures fertilizer rates on potato productivity and quality.