Evaluation of Pre- and Postemergence Herbicide Combinations for Broadleaved Weeds in Sugar Beet

Lithuania sugar beet growers have few herbicide options available for weed management. Six field trials were conducted at the Institute of Agriculture, Lithuania, in order to evaluate the effects of chemical weed management in sugar beet. Treatments included untreated and hand-weeded control and several rates of phenmedipham plus desmedipham plus ethofumesate, phenmedipham, ethofumesate, triflusulfuron, chloridazon, and metamitron. Pre- and postemergence and only postemergence applications similarly affected weed control. Phenmedipham plus desmedipham plus ethofumesate was more effective for controlling weeds when applied in combination with metamitron, triflusulfuron, and chloridazon. The significantly lowest efficacy for weed control was phenmedipham combined with ethofumesate and metamitron as compared to the phenmedipham plus desmedipham plus ethofumesate. Reducing the doses of phenmedipham plusdesmedipham plus ethofumesate from 114+89+140 g a.i. ha-1 to 91+71+112 g a.i. ha-1 and 68+53+84 g a.i. ha-1 in mixture with triflusulfuron resulted in the increase of weed biomass. Full (45 g a.i. ha-1) and reduced doses (30 g a.i. ha-1) of triflusulfuron with phenmedipham plus desmedipham plus ethofumesate similarly affected weeds. The herbicides investigated did not have any negative influence on sugar beet productivity and quality

Agrobiological Assessment of Short Rotations

Lithuania’s agricultural reform resulted in significant changes in land use, i.e. in the emergence of small individual farms. As a result, the formerly most popular 7, 8, 9-course crop rotations, or even 5-6-course crop rotations became inapplicable on small farms, especially on those not involved in animal production and cultivation of grass forage. Multiple-course crop rotations would disperse the same crops over several places, and the fields would not be unacceptably small. This is especially problematic for market farms, where it is intended to have 1-2-3 main crops and adequately alternate them. In foreign countries short rotations are a common practice in similar cases. However, in Lithuania short rotations have hardly been investigated, except for the sporadic research cases, therefore it is rather complicated to judge the feasibility of market crops growing in short rotations. When the area of cereals is increased in a crop rotation, it is more difficult to choose preceding crops, and continuous growing of crops becomes inevitable. It is of special relevance here to maintain soil fertility, moreover, the adverse effects of crops concentration manifest themselves much more severely than in any other system, namely, heavy occurrence of weeds, diseases and pests, soil depletion and fatigue. On cultivated Central Lithuania’s soils shortening of rotations and proper choice of preceding crops make it feasible to produce profitable, high quality agricultural production without depleting soil and without increasing weed and disease incidence.Žemės ūkio akademijaVytauto Didžiojo universiteta

CO2 dujų apykaita tarp dirvožemio ir atmosferos skirtingose ekosistemose: fizikinių, cheminių ir biologinių veiksnių sąveika

Lietuvos agrarinių ir miškų mokslų centro filialas Miškų institutasLietuvos agrarinių ir miškų mokslų centro filialas Žemdirbystės instituta

Ekologinio ir intensyvaus ūkininkavimo įtaka dirvožemio gyvybingumui

Lietuvos agrarinių ir miškų mokslų centro filialas Miškų institutasLietuvos agrarinių ir miškų mokslų centro filialas Žemdirbystės instituta

After-effect of long-term soil management on soil respiration and other qualitative parameters under prolonged dry soil conditions

Climatic conditions of environmental zone Nemoral 2 of Europe are favorable for agricultural development. However, more frequent events of hot air-waves and prolonged droughts occurring as a consequence of climate change lead to soil moisture content reduction down to the plant wilting point. Dry soil conditions may have negative consequences for soil as a habitat. The goal of this study was to evaluate the cumulative after-effect of long-term conventional (CT) and no-tillage (NT) application in combination with or without crop residues on soil physicochemical properties, microbiological activity, and soil respiration (SR) under prolonged dry soil conditions. Long-term CT with residue returning created a soil environment that was more resistant to dry conditions than NT. Longterm CT with residue returning created a qualitative soil environment in which the main direct determinants for SR were fungal (F) and bacterial (B) community and carbon/nitrogen ratio (C/N). Slightly weaker contributors for SR were available phosphorus (PAL), plant wilting point (PWP), plant available water (PAW), and urease activity (UR); however, they acted as indirect factors. Long-term spreading of residues on soil surface under NT determined the decrease in water capacity in mesopores and micropores. Significant reduction in field capacity and PWP was revealed, while PAW remained unchanged compared to NT with residues removed. Main direct determinants for SR were F and PAL. Slightly weaker indirect contributors for SR were B, dehydrogenase, UR, and PAWLietuvos agrarinių ir miškų mokslų centro Žemdirbystės institutasVytauto Didžiojo universitetasŽemės ūkio akademij