Netradicionālo mēslošanas līdzekļu izmantošanas efektivitāte ziemas ķiploku stādījumos = The efficiency of using non-traditional fertilizers in winter garlic plantations

Garlic (Allium sativum L.) is a widespread crop in vegetable production. The popularity of garlic is due to its bactericidal and antioxidant properties. Field trials with the winter garlic variety ‘Lubaša’ were established during two vegetation seasons of 2020/2021 and 2021/2022 in Terric Anthrosol (56°66' N, 23°75' E). Agrochemical indicators of the soil were the following: pHKCl 6.7, organic matter content – 3.8%, phosphorus (P2O5) content – 199 mg kgE−1, and potassium (K2O) content – 97 mg kgE−1 soil. Different variants of fertilizer mixtures with the digestates of pig manure (from LLC “Latvi Dan Agro”), cattle manure (from JSC “Ziedi JP”), and plant residue (from the farm “Līgo”), as well as wood ash (from LLC "Gren Jelgava") were used in the garlic plantations. Using these components, mixtures of relevant variants were prepared in the Biogas Scientific Laboratory of Latvia University of Life Sciences and Technologies. The ratio of digestate and wood ash in the mixtures was 3:1, and fertilizer rates for winter garlic were 15 and 30 t haE−1. The pre-plant was black fallow; the planting rate of winter garlic cloves was 1.6 t haE−1. Fertilizer was incorporated into the soil and garlic was planted by hand. The plot area in replicates was 2 m2 for recording the harvest. During the vegetation period, the development dynamics of winter garlic was registered, the harvest was recorded, and the quality of garlic bulbs was evaluated: the content of dry matter, crude protein, sulphur, phosphorus, potassium, and reducing sugars in dry garlic bulbs. Depending on the type of fertilizer, the yield varied between 8.92 and 9.15 t haE−1. The use of different types of digestates, including mixtures with wood ash, ensured a significant (p<0.05) increase in the yield of winter garlic bulbs which on average was by 0.71–0.94 t ha-1 larger compared to the control variant. Fertilizer mixture norms did not significantly affect the changes in crude protein content in garlic, thus it fluctuated between 6.1% and 7.8% in the total dry matter of the studied variants. The sugar content in the experimental samples of garlic was in the range of 0.53–0.70%. Depending on the fertilizer rate and type applied, the sulphur content in total dry matter was 0.28–0.70%.