The aim of the work was to evaluate the effect of different forms (granular or liquid) of nitrogen fertilizers on nitrate concentration and nitrogen leaching from a sandy loam Haplic Luvisol (LVh), to identify precipitation infiltration differences in fertilized and unfertilized soils. It was revealed that fertilization with nitrogen (on average 120 kg ha -1 N), compared to the unfertilized soil, increased the average annual nitrate concentration in leachate by 37.5-54.3% (P < 0.05). Slightly higher nitrate concentration was revealed after application of liquid fertilizer UAN 32. Compared to unfertilized soil, the impact of fertilizers on the increase of nitrate concentration in leachate was significant during summer (by 6.2-40.4 mg L -1 NO 3 ; P < 0.05) and autumn (by 32.2-52.3 mg L -1 NO 3 , or 49.8-80.8%; P < 0.05). Nitrogen leaching from nitrogen-fertilized soil increased by on average 6.3-9.5 kg ha -1 N per year, as compared with the unfertilized soil. Compared with ammonium nitrate and liquid complex fertilizer Lyderis 9-9-9, significantly more nitrogen (by 2.7-3.2 kg ha -1 N; P < 0.05) was leached from the soil applied with liquid fertilizer UAN 32. An average of 6.0-8.9% of applied nitrogen fertilizer content was leached per year. Thicker and more vigorous crops formed in fertilized soil, this reduced the average rainfall infiltration by 13.7-16.2% per year and by 31.6-38.8% during summer period, compared with unfertilized soil. This reduced the overall nitrogen leaching losses resulting from application of fertilizers.

Please use the following format when citing the article: Tripolskaja L., Ražukas A., Šidlauskas G., Verbylienė I. AbstractNew forms of mineral fertilizers containing bioactive components or substances controlling dissolution of granules in the soil are being developed to increase their efficiency and decrease negative environmental impacts. The present study was aimed to compare the effects of different complex fertilizers and complex fertilizer containing a nitrification inhibitor DMPP (3,4-dimethylpyrazole-phosphate) on barley and potato yield and quality, and nitrogen leaching. Experiments were carried out at Vokė Branch of the Lithuanian Research Centre for Agriculture and Forestry during 2012-2016. Experiments were performed in lysimetric facilities on a sandy loam Luvisol (LV) with a surface area of 1.75 m 2 and a test soil layer of 0.60 m thickness. Experimental treatments: 1) granular simple NPK fertilizers, 2) complex fertilizer nitrogenphosphate NP 33:3, 3) complex NPK fertilizer with bioactive components Eurofertil 35 and 4) complex NPK fertilizer with a nitrification inhibitor NovaTec classic. The investigated simple NPK and complex fertilizers (nitrogenphosphate NP 33:3, Eurofertil 35 and NovaTec classic) had a similar effect on the grain yield of barley, but significantly increased (7.7%, P < 0.05) the tuber yield of potatoes. Application of the fertilizer with a nitrification inhibitor improved the quality of barley grain and potato tubers and lowered the concentration of nitrates in tubers. Compared with simple fertilizers (ammonium nitrate, granular superphosphate and potassium chloride), the application of complex fertilizers nitrogenphosphate NP 33:3, Eurofertil 35, containing bioactive substances, and NovaTec classic, supplemented with a nitrification inhibitor, affected the dynamics of nitrogen leaching during specific periods, but no significant changes were estimated for nitrogen leaching per hydrological year.

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Analizuojami atmosferos kritulių infiltracijos pokyčiai dėl klimato veiksnių varijavimo Rytų Lietuvoje. Infiltracijos stebėjimai atlikti 1987–2014 m. Lietuvos agrarinių ir miškų mokslų centro Vokės filiale, lizimetriniuose įrenginiuose. Lizimetrų paviršiaus plotas – 1,75 m2, tiriamojo dirvožemio (sandy loam Haplic Luvisol) sluoksnis – 0,60 m. Nustatyta, kad Lietuvoje, didėjant vidutinei oro temperatūrai ir ilgėjant pavasario bei rudens laikotarpiams, 1987–2014 m. išaugo metinė kritulių infiltracija. Pokyčių trendas aprašomas regresijos lygtimi y = 9,5817x2 – 30,866x + 315,87, R2 = 0,357. Infiltracijos padidėjimas fiksuojamas pavasario, vasaros ir rudens laikotarpiais, o žiemą – mažėja. Infiltracijos padidėjimas šiltuoju metų laikotarpiu, kai žemės ūkio naudmenos tręšiamos įvairiomis trąšomis, gali skatinti cheminių elementų išplovimą iš viršutinio dirvožemio sluoksnio.