Research objective. The study was aimed to establish the competitive peculiarities of the multi-component agrocenose (maize, living mulches, weeds) and its effects on soil properties under sustainable farming conditions. Research tasks. To accomplish the research objective the following tasks were set - to study: 1. The influence of living mulches, grown in a maize monocrop, on soil physical properties (soil moisture dynamics, shear resistance, penetration resistance, soil structure and its stability), chemical characteristics (total nitrogen, available phosphorus and potassium content, pH) and biological characteristics (urease and saccharase activity); 2. The dynamics of biomass accumulation of living mulches and weeds; 3. The impact of living mulches on weed infestation in a maize crop and on weed seed contamination in a ploughlayer; 4. Maize crop irradiance conditions and their influence on different components of the agrophytocenose; 5. Projection coverage of maize inter-rows; 6. Maize productivity and biometric indicators; 7. The relationships between the factors tested. / Tyrimų tikslas – įvertinti daugiakomponentės agrocenozės – kukurūzų, tarpinių augalų, piktžolių – konkurencinius ypatumus ir jos poveikį dirvos savybėms tvaraus ūkininkavimo sąlygomis. Tyrimų uždaviniai. Tyrimų tikslui pasiekti numatyta ištirti: 1. Įsėlinių tarpinių augalų, augusių kukurūzų monopasėlyje, poveikį dirvos fizikinėms (dirvos drėgnio dinamikai, šlyties pasipriešinimui, kietumui, dirvos struktūrai ir jos patvarumui), cheminėms (suminio azoto, judriojo fosforo ir kalio kiekiui, pH), biologinėms (ureazės ir sacharazės aktyvumui) savybėms; 2. Įsėlinių tarpinių augalų ir piktžolių biomasės kaupimosi dinamiką; 3. Įsėlinių tarpinių augalų poveikį kukurūzų pasėlio piktžolėtumui bei armens užterštumui piktžolių sėklomis; 4. Kukurūzų pasėlio apšvitos sąlygas ir jų poveikį skirtingiems agrofitocenozės komponentams; 5. Kukurūzų tarpueilių projekcinį padengimą; 6. Kukurūzų produktyvumo ir biometrinius rodiklius; 7. Tiriamųjų veiksnių sąsajas ir poveikio priežastingumą.

Conservation tillage programs have been successfully implemented for many agronomic cropping systems, but adoption of reduced tillage for vegetable crops has been slow. As many conventionally managed conservation tillage programs rely on synthetic herbicides for clean cultivation, alternative methods must be devised to suppress weed pressure and reduce reliance on mechanical cultivation to aid in the development of reduced tillage programs for organic cropping system. Strip tillage is a reduced tillage method that is well suited to vegetable crop production, and the utilization of cover crops and living mulches between rows provides a viable weed management option for organic systems. The adoption of reduced tillage and the inclusion of cover crops and living mulches have the potential to alter the agroecosystem in ways that impact plant development and crop yield, and augment weed, insect and disease pressure. The current study focuses on the use of strip tillage and the interplanting of spring-seeded living mulches and overwintered cover crops for early-season organic broccoli production. Data were collected on ground cover provided by cover crops and living mulches, crop physiological status (petiole sap nitrate, photosynthetic rate, plant growth and crop biomass) and pest pressure (weed relative abundance, insect density and disease incidence and severity). Living mulches provided the greatest ground coverage when cover crop establishment was poor; however, when cover crops produced a large amount of biomass, living mulch establishment was suppressed. Decreases in herbivorous pests and suppression of grassy and cool-season weed species were also observed, indicating that strip tillage and the use of spring-seeded living mulches and overwintered cover crops may provide beneficial pest management strategies. Decreases in crop growth and biomass, and decreases in petiole sap nitrate were observed, however, indicating reductions in crop vigor and yield may be expected with the implementation of strip tillage and living mulch crops. It is suggested that the utilization of strip tillage and living mulch crops may provide benefits to pest management which may outweigh declines in yield.

Magistrantūros studijų baigiamajame darbe pateikiami įsėtų įsėlių įtakos pasėlio piktžolėtumui, morfometriniams ir produktyvumo rodikliams tyrimo duomenys. Darbo objektas – kukurūzų (Zea mays) monopasėlis, tarpiniai įsėliniai augalai, piktžolės. Darbo metodai: Eksperimentas vykdytas 2009-2011 m. Aleksandro Stulginskio universiteto (buvęs LŽŪU) Bandymų stotyje sekliai glėjiško karbonatingo išplautžemio (Calc(ar)i-Epihypogleyic Luvisol, LVg-p-w-cc(sc)) dulkiško priemolio sąlygomis. Eksperimento variantai: 1. ravėjimas 1-2 kartus (kontrolinis variantas) (R2K); 2. vasarinių rapsų (Brassica napus L.) tarpinis pasėlis (VRTP); 3. baltųjų garstyčių (Sinapis alba L.) tarpinis pasėlis (BGTP); 4.vasarinių miežių (Hordeum vulgare L.) tarpinis pasėlis (VMTP); 5. gausiažiedžių (vienamečių) svidrių (Lolium multiflorum Lamk.) tarpinis pasėlis (GSTP); 6. apyninių liucernų (Medicago lupulina L.) tarpinis pasėlis (ALTP); 7. persikinių dobilų (Trifolium resupinatum L.) tarpinis pasėlis (PDTP); 8. raudonųjų dobilų (Trifolium pratense L.) tarpinis pasėlis (ADTP). Darbo rezultatai. Piktžolių bendroji sausoji masė priklausė nuo tarpinių įsėlinių augalų masės. Nustatytas priklausomumas tarp tarpinių įsėlinių augalų sausosios masės ir visų piktžolių sausosios masės (r=-0,444). Labiausiai piktžolės išplito tarpiniuose pasėliuose, anksti šienavimo metu eliminuotuose iš kukurūzų tarpueilių: baltųjų garstyčių, vasarinių miežių bei vasarinių rapsų. Mažiausia sausoji piktžolių masė nustatyta... [toliau žr. visą tekstą] / In the final work of master degree studies there is given data of investigation of influence of living mulch on crop weediness, morphometric and productivity indicators. The object of the work – maize (Zea mays) monoculture, living mulch plants, weeds. The methods of work: The experiment was performed in 2009-2011 in the Experimental station of Aleksandras Stulginskis under the conditions of silty loam Luvisol ((Calc(ar)i-Epihypogleyic Luvisol, LVg-p-w-cc(sc)). The treatments of experiment: 1. Hand weeding (control variation) (R2K); 2. Spring rape (Brassica napus L.) living mulch (VRTP);3. White mustard (Sinapis alba L.) living mulch (BGTP); 4. Spring barley (Hordeum vulgare L.) living mulch (VMTP); 5. Italian ryegrass (Lolium multiflorum Lamk.) living mulch (GSTP); 6. Black medic (Medicago lupulina l.) living mulch (ALTP); 7.Persian clover (Trifolium resupinatum L.) living mulch (PDTP); 8. Red clover (Trifolium pratense L.) living mulch (ADTP). The results of the work: The total dry mass of the weeds was dependant upon the mass of mulch plants. The dependence indicated between the dry mass of mulch plants and the dry mass of all weeds (r=-0,444). Mostly weeds expanded in the intermediate crops which were moved from the interrows of maize: white mustard, spring barley and spring rape. The lowest dry mass of weeds was indicated in the mulch of ryegrass, Persian and red clover. These mulches produced essentially highest biomass. In the field experiment the most of... [to full text]

Reduced tillage and living mulches are alternative management strategies that can improve soil quality by minimizing disturbance and building soil organic matter. Weed suppression by these two practices alone is often insufficient to avoid crop yield losses, but their performance in an integrated system is not well understood. This project investigated the production of bell pepper (Capsicum annuum L.) and dry bean (Phaseolus vulgaris L.) in conventional tillage and strip tillage with a living mulch of teff (Eragrostis tef Zucc.) and Korean lespedeza (Kummerowia stipulacea Maxim.). Yields of pepper and bean were generally higher under conventional tillage without living mulch. Weed biomass was not influenced by tillage, and was adequately suppressed by teff in a year when conditions for teff growth were favorable. Mowing appeared to suppress weed growth but not living mulch growth. Soil nitrate and ammonium concentration was generally higher under conventional tillage without living mulch. Delaying living mulch seeding by 15 days after crop establishment generally did not affect weed suppression or crop yield. Soil aggregate stability was not consistently affected by tillage or living mulch. Increased mowing frequency, living mulch planting delay, or distance between the crop row and the living mulch may be necessary to achieve acceptable yields with living mulches.

Vegetable producers may benefit from integrating living mulches into their operations to manage weeds and improve soil quality. Living mulches, however, can reduce vegetable yield through competition. Here we investigate strip tilling into living mulches and then direct seeding a vegetable crop in the strip till zone as a production practice to limit competition. We further investigate the use of two surface-applied mulches, a newsprint hydromulch and a compost blanket, for weed control within the strip till zone. In field conditions, living mulches reduced vegetable yield by 49-84% and the use of the newsprint hydromulch and compost blanket reduced weed biomass by 84% and 85% respectively. In greenhouse conditions, a 50% reduction in the hydromulch application rate used in the field experiment achieved similar weed control, suggesting an application rate of 6.4 L m-2 or a mulch strength of 0.6 MPa may be sufficient for weed control with a hydromulch.

Increasing food, feed, fiber, biofuel production on decreasing amounts of arable land while simultaneously enhancing ecosystem services is challenging. Strategic inclusion of winter rye (<i>Secale cereale</i>) for biomass, silage, grain and Kura clover (<i>Trifolium ambiguum</i>) living mulch into existing Midwestern cropping systems may offer alternative economic income for farmers without displacing or reducing yields of primary crops. Research was conducted at the Purdue Water Quality Field Station (WQFS) where net balances of water, carbon, nitrogen, and radiation can be measured, and greenhouse gas (GHG) emissions are monitored. The agronomic performance of a corn-soybean rotation and continuous corn (controls) were compared to novel systems that included the use of rye cover cropping and Kura clover co-cropping. Rye was harvested for biomass/silage at heading immediately followed by corn or soybean planting. Continuous corn receiving 69 kg N ha^-1was planted into an establishment of Kura clover sod. Controls included these same systems without the rye or clover. GHG samples were taken via the static chamber method and tile-drained water sub-samples were collected, analyzed for nitrate, and load losses calculated. Biomass composition was determined and used to calculate herbage theoretical ethanol (EtOH) yields. Cereal rye did not significantly decrease corn or soybean grain yield. Averaged across years, Kura clover significantly depressed corn grain yields by nearly 70%. Kura clover significantly reduced flow-weighted tile drainage nitrate (NO₃^-) concentrations, however cereal rye did not. Reductions in flow-weighted tile drainage nitrate (NO₃^-) concentrations were found to largely occur during Quarter two (April, May, June). Cover crops did not significantly reduce annual tile drained NO₃^- load losses in most cases, however, they did significantly reduce annual N₂O emissions. Cumulative annual CH₄ emissions were not significantly altered. Annual CO₂emissions were higher after the introduction of Kura clover and not significantly altered following the introduction of cereal rye. Averaged across years, theoretical ethanol yields in the Kura clover system produced 2,752 L EtOH ha^-1, whereas EtOH production in cereal rye systems ranged from 3,245 to 4,210 L EtOH ha^-1. Theoretical ethanol yields of continuous corn and rotational controls ranged from 2,982 to 3505 L EtOH ha^-1 for these same systems without the cereal rye of Kura clover. These data suggest that a multipurpose approach to cover crop inclusion can provide both environmental and economic advantages worthy of consideration.