ECONOMICAL EVALUATION OF REDUCED INTENSITY TILLAGE SYSTEMS, STRAW AND GREEN MANURE COMBINATIONS

Since 1999, a long-term field experiment has been done at the Experimental Station of Vytautas Magnus University (former Aleksandras Stulginskis University) at 54º52′50 N latitude and 23º49′41 E longitude. The soil of the experiment site is Epieutric Endocalcaric Endogleyic Planosol (Endoclayic, Aric, Drainic, Humic, Episiltic) according to WRB (2014). The objective of our investigations was to assess the long-term impact of reduced intensity tillage systems, straw and green manure combinations on productivity and economical evaluation. A short crop rotation was introduced: winter wheat, spring barley, spring rape. The results were obtained in 2000-2017. Sustainable agroecosystems are able to maintain their condition, productivity and biodiversity, as well as their integrity over time and in the context of human activity and use. The sustainability of agroecosystems is inseparable from the stability of their productivity. In order to illustrate this, we estimated crop productivity differences % from the year 2000 to 2017. In terms of crop productivity, all the tested long-term complex measures of different intensities were similar, both when comparing with average productivity that year and when estimating cumulative differences com-pared with deep ploughing. &nbsp

Pine forest self regeneration in non-clear cutting areas in Kazlų Rūdos Educational State Forest Enterprise

Magistro darbe tiriamas savaiminis pušynų žėlimas neplynųjų kirtimų kirtaviečių, Kazlų Rūdos miškų urėdijoje. Darbo objektas – brandūs, ketvirtos miškų grupės pušynai, augantys Kazlų Rūdos miškų urėdijojos Nb, Lb augavietėse. Darbo metodika. Tyrimai atlikti 2010 m. vasarą, įvertinant per praėjusius šešerius metus susiformavusius žėlinius atvejinių kirtimų kirtavietėse. Kiekvienoje kirtavietėje buvo tolygiai išdėstytos apskaitos aikštelės (juostos) sąlyginai - vienodais atstumais sklypų įstrižainių kryptimis, siekiant atlikti žėlinių apskaitą ir įvertinti jų kokybę. Miško želdinių ir žėlinių vidutinis aukštis nustatomas kiekvienoje apskaitos aikštelėje išmatavus 5 vidutinio aukščio projektuotų medžių rūšių medelių aukščius ir apskaičiavus jų vidurkį. Nepageidaujamų medžių ir krūmų vidutinis aukštis nustatomas kiekvienoje apskaitos aikštelėje išmatavus 5 vidutinių nepageidaujamų medžių arba krūmų aukščius ir apskaičiavus jų vidurkį. Medelių aukščiai matuojami 10 cm tikslumu. Darbo rezultatai. Kazlų Rūdos MU Braziūkų ir Agurkiškės girininkijose neplynųjų kirtimų kirtavietėse po pirmo kirtimų atvejo pomiškis susiformuoja per 3- 4 metus. Vidutinis septynių kirtaviečių žėlinių tankis 5430 vnt./ha. Žėlimo efektyvumas priklauso nuo augavietės. Po pirmojo kirtimo atvejo Lb augavietėje pušis atžėle 38% gausiau nei Nb augavietėje. Motininio medyno rūšinė sudėtis įtakoja savaiminukų gausą ir sudėtį po kirtimų. Didėjant pušies kiekiui medynų sudėtyje ( 70- 100%), didėja pušies dalis savaiminukų rūšinėje sudėtyje ( 76- 81%). Mūsų tirtu atveju neplynojo kirtimo kirtavietėse, nederlingose augavietėse ( Nb, Lb) po 3- 4 metų susiformavo geri želdiniai iš tikslinių medžių rūšių. Gera žėlinių kokybę nulemia kirtimo laiko derinimus su sėkliniais metais bei dirvos purenimas bei priežiūra.In this master thesis was investigated pine self regeneration in non-clear cutting areas in Kazlų Rūdos Educational State Forest Enterprise. Object – mature, 4th forest group pine stands, growing in Kazlų Rūdos Forest Enterprise, Nb, Lb sites. Methodology. The investigation was performed in summer 2010, evaluating the regeneration, formed during the last six years in shelter-wood cutting areas. In each cutting area were evenly arranged sample plots (stripes) by relatively equal distances to the diagonal directions, in purpose to perform the accounting of regeneration and to evaluate their condition. Average height of forest regeneration was determined in each sample plot after evaluating the average height of 5 designed trees height and counted their average. Average height of undesirable tree species was determined after evaluating 5 average trees height of undesirable tree species in each sample plot. Trees height were measured in 10 cm accuracy. Results. In Kazlų Rūdos Forest Enterprise Braziūkų and Agurkiškės Forest Districts in non-clear-cutting areas after first cutting the understory forms in 3- 4 years. The average density of regeneration in seven areas was 5430 per ha. Regeneration efficiency depends on the site. After first cutting in Lb site, pine has regenerated 38% more efficiently than in Nb site. Mother stand tree species composition has influence to regeneration abundance and species composition. Together with the increment of pine share in stand ( 70- 100%), pine share in regeneration species composition is increasing too ( 76- 81%). Due to our investigated case, in non-clear cutting areas infertile sites ( Nb, Lb) after 3- 4 years good regeneration with nobel tree species has formed. Good regeneration quality was related to time combination with seed year and suitable soil preparation.Žemės ūkio akademijaVytauto Didžiojo universiteta

Sustainability of agroecosystem and carbon sequestration as effect of long-term complex measures

Lietuvos dirvožemio ir klimatinėmis sąlygomis atlikti įvairaus intensyvumo žemės dirbimo tyrimai teikia tik fragmentines žinias. Pirmą kartą giliau glėjiškame pasotintame palvažemyje (pagal WRB 2014 klasifikaciją – Epieutric Endocalcaric Endogleyic Planosol (Endoclayic, Aric, Drainic, Humic, Episiltic) ilgalaikiai agroekosistemų tvarumo pokyčiai įvertinti sistemiškai, to siekiant taikytos ilgalaikės kompleksinės priemonės. Išsiaiškinta, kad pastovus šiaudų paskleidimas bei paviršinis purenimas su žaliąja trąša ar be jos ir tiesioginė sėja į neįdirbtą dirvą efektyviai didina organinės anglies sankaupas dirvožemyje, yra efektyvi dirvožemio derlingumo atkūrimo ir didinimo priemonė, leidžianti sumažinti neigiamą ūkininkavimo poveikį klimato kaitai.Research on soil tillage of various intensities done under Lithuania’s soil and climate conditions has provided only fragmentary knowledge. This is the first study, conducted on an Epieutric Endocalcaric Endogleyic Planosol (Endoclayic, Aric, Drainic, Humic, Episiltic) (according to WRB 2014), to undertake a systematic assessment of long-term changes in the sustainability of agroecosystems as influenced by long-term complex measures. In this study, was ascertained that regular spreading of straw and shallow loosening of soil with or without green manure and direct drilling increase organic carbon stocks in the soil and are efficient means for soil fertility restoration and increasing and enable minimisation of the negative impacts of farming on the climate change.Žemės ūkio akademijaVytauto Didžiojo universiteta

Soil penetration resistance, aggregation and stability after long-term reduced tillage, no-till and residue management

Long-term fixed experiment, set up in 1999, at the Experimental Station of Vytautas Magnus University. The soil of the experimental site is Epieutric Endocalcaric Endogleyic Planosol (Endoclayic, Aric, Drainic, Humic, Episiltic)) according to WRB 2014 classification. The long-term experiment was laid out in a split-plot design with 4 replications and a total of 48 plots. The initial plot size is 102 m2 (6 m x 17 m), the harvested plot size is 30 m2 (15 m x 2.0 m). The following crop rotation sequence was employed: spring rape, winter wheat, spring barley. In one part of the experiment, the straw was removed (R), and in the other part the straw was chopped and spread (S). All tillage systems were studied in both parts of the experiment, i.e. with straw removed and straw chopped and spread. Long-term application of reduced tillage results in a significant increase in soil penetration and soil shear resistance. The lesser the tillage depth, the higher the soil penetration and soil shear resistance. The effect of plant residue spreading is lower. Meanwhile, soil structural stability was highly dependent on soil tillage. Shallow rotovating before sowing increased soil structural stability by up to 1.8 times, incorporation of green manure of white mustard into the soil by a rotovator before sowing increased it by up to 2.0 times and direct drilling by up to 1.9 times, compared with deep ploughingAgronomijos fakultetasVytauto Didžiojo universiteta

Long-term impact of reduced intensity tillage systems, straw and green manure combinations on soil aggregation, water capacity, pore structure and bulk density

Vytauto Didžiojo universitetasŽemės ūkio akademij

Šiaudų panaudojimo galimybės dirvožemio ir augalų derlingumui palaikyti : mokslinė rekomendacija

Vytauto Didžiojo universitetasŽemės ūkio akademij

Long-term impact of reduced intensity tillage systems, straw and green manure combinations on soil properties

Vytauto Didžiojo universitetasŽemės ūkio akademij

Long-Term Impact of Reduced Tillage Intensity in Combination with Straw and Green Manure Incorporation on Earthworms in the Soil

Since 1999, a long-term field experiment has been done at the Experimental Station of Aleksandras Stulginskis University at 54º52′50 N latitude and 23º49′41 E longitude. The soil of the experiment site is Epieutric Endocalcaric Endogleyic Planosol (Endoclayic, Aric, Drainic, Humic, Episiltic) according to WRB (2014), texture at 0–20 cm depth is silty medium loam (33.7% sand, 50.3% silt, 16.0% clay), at 20–40 cm depth – silty light loam (35.4% sand, 51.1% silt, 13.5% clay). The objective was to long-term impact of reduced tillage intensity in combination with straw and green manure incorporation on earthworms in the soil. A short crop rotation was introduced: winter wheat, spring barley, spring rape. The results were obtained in 2013-2014 when winter wheat and spring rape was grown. According to two factor field experiment, the straw (factor A) was removed (R) from one part of the experimental field and on the other part of the field all straw yield was chopped and spread (S) at harvesting. As subplot 6 different tillage systems (factor B) were investigated: conventional ploughing (CP) at 23–25 cm depth in autumn, shallow ploughing (SP) at 10–12 cm depth in autumn, shallow loosening (SL) with sweep cultivator and disc harrow at 8–10 cm depth in autumn, shallow rotovating (SR) at 5–6 cm depth before next crop sowing, catch cropping for green manure and rotovating (GMR) at 5–6 cm depth before next crop sowing, no-tillage (NT), direct drilling. Catch crop white mustard (Sinapis alba L.) for green manure was under sown on stubble only in GMR plots just after winter wheat and spring barley harvest. The trials were replicated four times. The treatments were arranged using a split-plot design. The total size of each plot was 102 (6 × 17) m2 and net size was 30.0 (2.0 × 15) m2Vytauto Didžiojo universitetasŽemės ūkio akademij

Carbon Sequestration as Reflected by Long-Term Complex Measures

Vytauto Didžiojo universitetasŽemės ūkio akademij