• Authors:
    • Topa, D.
    • Cara, M.
    • Jitareanu, G.
    • Raus, L.
  • Source: Annals of the University of Craiova - Agriculture, Montanology, Cadastre Series
  • Volume: 40
  • Issue: 1
  • Year: 2010
  • Summary: The project aims the sustainable development in Romania, soil, water and carbon conservation, and counter-balances the effects of global climate change. Research carried out aimed at developing fundamental knowledge through in-depth inquiries of soil quality indicators of Moldavian Plain, regarding integrated management of soil and water. Research carried out also aimed to quantify the influence of agricultural technologies on physic, hydric, thermic, nutrient and biological soil regime, and ecological impact of these changes on ecological, energetically, hydrological, biogeochemical and breathing soil function, in specific areas of Moldavian Plain. The experiment was conducted at the Didactic Station of the "Ion Ionescu de la Brad" University of Agricultural Sciences and Veterinary Medicine of Iasi, Ezareni Farm, during Analele Universitatii din Craiova, seria Agricultura - Montanologie - Cadastru Vol. XL/1 2010 farming years 2007-2009. The experimental site is located in the East part of Romania on a chambic chernozem, with a clay-loamy texture, 6.8 pH units, 3.7% humus content and a medium level of fertilization. The soil has high clay content (38-43%) and is difficult to till when soil moisture is close to the wilting point (12.2%). We have investigated three variants of soil tillage system - conventional tillage, minimum tillage and no-till - in the crop rotation made of wheat and raps. This paper presents the results obtained in winter wheat growing as concerns the influence of the tillage method on some soil physical characteristics. Tillage system modify, at least temporarily, some of the physical properties of soil, such as soil bulk density, penetration resistance, soil porosity and soil structural stability. All the tillage operation was significantly different in heir effects on soil properties. The results indicate that soil tillage systems must be adjusted to plant requirements for crop rotation and to the pedoclimatic conditions of the area.
  • Authors:
    • Sandor, M.
    • Domuta, C.
    • Vuscan, A.
    • Domuta, C.
    • Samuel, A.
  • Source: Research Journal of Agricultural Science
  • Volume: 42
  • Issue: 3
  • Year: 2010
  • Summary: The importance of phosphatase for plant nutrition has repeatedly been pointed out. In most soils, the organically bound P-fraction is higher than the inorganic. Phosphorus uptake by plants requires mineralization of the organic P-component by phosphatases to orthophosphate. Phosphatases are inducible enzymes that are produced predominantly under conditions of low phosphorus availability. Phosphatases are excreted by plant roots and by microorganisms. Microbial phosphatases dominate in soils. The phosphomonoesterases, so-called phosphatases differ in their substrate specificity and their pH optimum. One can thus differentiate between acid and alkaline phosphatases in the soil. Phosphatase activities were determined in the 0-20-, 20-40- and 40-60-cm layers of a preluvosoil submitted to a complex tillage (no-till and conventional tillage), crop rotation (2- and 3-crop rotations) and fertilisation [mineral(NP) fertilisation and farmyard-manuring] experiment. It was found that the activities decreased in the order: acid phosphatase activity > alkaline phosphatase activity. Each activity decreased with increasing sampling depth. No-till-in comparison with conventional tillage - resulted in significantly higher soil phosphatase activities in the 0-20-cm layer and in significantly lower activities in the deeper layers. The soil under maize or wheat was more phosphatase-active in the 3- than in the 2-crop rotation. In the 2-crop rotation higher soil phosphatase activities were recorded under wheat than under maize. Farmyard-manuring of maize - in comparison with its mineral fertilisation - led to a significant increase in each activity.
  • Authors:
    • Molnar, L. J.
    • Blackshaw, R. E.
    • Moyer, J. R.
  • Source: Canadian Journal of Plant Science
  • Volume: 90
  • Issue: 4
  • Year: 2010
  • Summary: Farmers on the Canadian prairies are interested in including legume cover crops in their cropping systems to reduce fertilizer inputs and improve farm sustainability. A field study was conducted to determine the merits of establishing alfalfa ( Medicago sativa L.), red clover ( Trifolium pratense L.) or Austrian winter pea ( Pisum sativum L.) cover crops in fall or in spring with winter wheat ( Triticum aestivum L.). Spring-planted legumes emerged well within the winter wheat crop, but their growth was limited under these semi-arid conditions. Fall-planted red clover had low plant densities following winter in two of three experiments and fall-planted winter pea reduced winter wheat yield by 23 to 37% compared with the no cover crop control. In contrast, fall-planted alfalfa exhibited good winterhardiness, provided some weed suppression without reducing winter wheat yield, caused only a slight reduction in soil water content, and contributed an extra 18 to 20 kg ha -1 of available soil N at the time of seeding the following spring crop. Additionally, fall-planted alfalfa increased the yield of succeeding canola ( Brassica napus L.) in unfertilized plots in two of three experiments. Further research is warranted to better understand the agronomic and economic benefits of alfalfa-winter wheat intercrops under a wider range of environmental conditions.
  • Authors:
    • Alda, L.
    • Baluta, D.
    • Manea, D.
    • Alda, S.
    • Lazureanu, A.
    • Caciu, G.
    • Circiu, L.
  • Source: Journal of Horticulture, Forestry and Biotechnology
  • Volume: 14
  • Issue: 2
  • Year: 2010
  • Summary: The research was conducted in 2008-2009 and followed the influence of six plants run on the cover of plants with weeds plants culture and production of winter wheat. Predominant weeds were Veronica hederifolia, Viola arvensis, Polygonum Convolvulus, Convolvulus arvensis and Stellaria media. The degree of reduction of weeds, depending on pre-plant fluctuated between 17,84 and 28%, 43% in 2008 and between 20.49% and 29.58% in 2009. Production is directly proportional to the absolute level of covering plants with weeds plants, beings from 38.05 q/ha and 43.26 q/ha in 2008 and between 44.72 q/ha and 52.08 q/ha in 2009.
  • Authors:
    • Dimitrova-Doneva, M.
    • Petkova, R.
  • Source: Agricultural Science and Technology
  • Volume: 2
  • Issue: 3
  • Year: 2010
  • Summary: A study has been conducted at the Experimental Station of Agriculture, Sredets to establish the effect of predecessor and mineral fertilization on chemical composition and energy value of wintering oats grain. The object of this study was wintering oat ( Avena sativa L) variety Jubile cultivated after predecessors (A): stubble (A 1), sorghum ( Sorghum vulgare Pers) - (A 2) and rape ( Brassica napus var. oleifera L) - (A 3) and fertilization, kg/ha - (B): N 40P 100K 50-B 1; N 80P 100K 50-B 2; N 120P 100K 50-B 3 and B 0-control N 0P 100K 50. The study covers chemical analysis of wintering oats grain made by Weende method. Calculations for the nutritive value of feed grain based on data obtained from chemical analysis were made (for ruminants) expressed in gross energy (GE) - MJ/kg dry substance, metabolizable energy (ME) - MJ/kg dry substance, feed units for milk (FUM, kg) and feed units for growth (FUG, kg) of dry substance - by using empirical equations. It was found that the predecessors stubble and rape increase the content of crude protein, crude fat and crude fibers in oats by 10.5 and 12.1%, 5.2 and 3.9%, 5.6 and 1.2%. The content of minerals and nitrogen-free extract (NFE) was the highest after predecessor sorghum. Increasing the doses of nitrogen fertilizer led to increasing the content of crude protein and fibers in grains on average by 14.4% and decreases the content of crude fats, ash and NFE by 7.0%, 3.2% and 3.4%, respectively. The differences in chemical composition of oat grains did not have a significant impact on its energy value expressed by GE, ME, (FUM) and (FUG).
  • Authors:
    • Chen, L.
    • Sun, Q.
    • Li, H.
    • Fang, S.
  • Source: Agroforestry Systems
  • Volume: 79
  • Issue: 2
  • Year: 2010
  • Summary: The importance of agroforestry systems in CO 2 mitigation has become recognized worldwide in recent years. However, little is known about carbon (C) sequestered in poplar intercropping systems. This study aims compare the effects of three poplar intercropping designs (configuration A: 250 trees ha -1; configuration B: 167 trees ha -1 and configuration C: 94 trees ha -1) and two intercropping systems (wheat-maize cropping system and wheat-soybean cropping system) on biomass production and C stocks in poplar intercropping systems. The experiment was conducted at Suqian Ecological Demonstration Garden of fast-growing poplar plantations in northwestern Jiangsu, China. A significant difference in C concentration was observed among the poplar biomass components investigated ( P≤0.05), with the highest value in stemwood and the lowest in fine roots, ranging from 459.9 to 526.7 g kg -1. There was also a significant difference in C concentration among the different crop components ( P≤0.05), and the highest concentration was observed in the maize ear. Over the 5-year period, the total poplar biomass increased with increasing tree density, ranging from 8.77 to 15.12 tonnes ha -1, while annual biomass production among the crops ranged from 4.69 to 16.58 tonnes ha -1 in the three configurations. Overall, total C stock in the poplar intercropping system was affected by configurations and cropping systems, and configuration A obtained the largest total C stock, reaching 16.7 tonnes C ha -1 for the wheat-soybean cropping system and 18.9 tonnes C ha -1 for the wheat-maize cropping system. Results from this case study suggest that configuration A was a relative optimum poplar intercropping system both for economic benefits and for C sequestration.
  • Authors:
    • Kosterna, E.
    • Franczuk, J.
    • Zaniewicz-Bajkowska, A.
  • Source: Acta Agriculturae Scandinavica Section B-Soil and Plant Science
  • Volume: 60
  • Issue: 5
  • Year: 2010
  • Summary: A field experiment was conducted during the period 2002-2006 at the Experimental Farm in Zawady, located in the mid-eastern part of Poland, to evaluate the effect of date of mulch ploughing down (autumn, spring, left till cabbage harvest) and the plant mulches [phacelia ( Phacelia tanacetifolia Benth.), vetch ( Vicia sativa L.), serradella ( Ornithopus sativus), and oat ( Avena sativa L.)] on the weed pressure in red cabbage ( Brassica oleracea L. var. capitata L. f. rubra) in the first and onion ( Allium cepa L. var. cepa Helm.) in the second year after mulching. The biomass yield of plant mulches, total cabbage and onion yields, and biomass and number of weeds before planting and harvest of cabbage and before sowing and harvest of onion were assessed. Weed infestation was determined by the quantitative-weighting method. The biomass yields of phacelia and oat amounted to 26.6 and 24.8 t.ha -1, respectively, and were almost 2.5-times higher than biomass yields of serradella and vetch. The average cabbage and onion yields were 45.8 and 41.9 t.ha -1, respectively. The yields of vegetables following mulches were higher than the yields recorded in the unmulched control. The weed species most often found in the experiment were Viola arvensis Murr., Capsella bursa pastoris, Matricaria indora L., Chenopodium album L., and Stellaria media (L.) Vill. Of the examined dates of mulch ploughing down, the spring-incorporated mulches were most effective in reducing the number of weeds in cabbage whereas the nonincorporated mulches showed such an effect in onion. Nonlegumes (phacelia and oat) used as mulch produced higher fresh biomass yields than did vetch and serradella. Oat and phacelia mulches significantly reduced the fresh biomass and number of weeds before cabbage planting. Additionally, oat mulch reduced the fresh biomass of weeds before cabbage harvest. Also, oat and phacelia mulches reduced the number of weeds before onion harvest.
  • Authors:
    • Rosa, R.
    • Kosterna, E.
    • Zaniewicz-Bajkowska, A.
    • Franczuk, J.
    • Pniewska, I.
    • Olszewski, W.
  • Source: ACTA SCIENTIARUM POLONORUM-HORTORUM CULTUS
  • Volume: 9
  • Issue: 2
  • Year: 2010
  • Summary: Very important element of proecological vegetables cultivation it is cover plants applied. They have favourable influence on the soil environment, indicated the possibility of limiting mineral fertilizer use and also reduce an application of herbicides, allow to keep soil fertility and in this same achieve high and good quality of yield. An experiment was carried out in 2002-2005 at the Experimental Farm in Zawady belonging to University of Podlasie. The objective of the study was the effect of cover plants (phacelia, spring vetch, serradella and oat) ploughed down in the autumn, spring or retained on the soil surface as a cover crop on the yield of red and savoy cabbage, and dry matter and vitamin C contents in white and savoy cabbage was investigated. The effects of covers were compared to the uncovered control. White cabbage cv. 'Masada F 1', red cabbage cv. 'Koda' and savoy cabbage cv. 'Wirosa F 1' were cultivated. Irrespective of the date of ploughing down of cover plants, serradella was the best plant cover preceding red cabbage, and phacelia was most beneficial when preceded savoy cabbage. Oat cover ploughed down in the autumn favoured dry matter accumulation, when spring-incorporated, stimulated vitamin C in white cabbage. The autumn-incorporated phacelia cover resulted in the greatest dry matter and vitamin C contents in savoy cabbage.
  • Authors:
    • O'Donovan, J.
    • Harker, K.
    • Clayton, G.
    • Dosdall, L.
    • Hummel, J.
  • Source: Biological Control
  • Volume: 55
  • Issue: 3
  • Year: 2010
  • Summary: Several natural enemies regulate populations of root maggots ( Delia spp.) (Diptera: Anthomyiidae) in canola ( Brassica napus L.) in western Canada, among them the rove beetles Aleochara bilineata Gyllenhal and Aleochara verna Say (Coleoptera: Staphylinidae) and the hymenopteran Trybliographa rapae Westwood (Hymenoptera: Figitidae). Intercrops of canola and wheat ( Triticum aestivum L.) can be part of an integrated pest management strategy to reduce damage by Delia spp. to canola. We investigated several intercropping regimes of canola and wheat to determine effects on parasitism of Delia radicum (L.) and activity densities of adult A. bilineata and A. verna. Studies were conducted over four site-years in central Alberta, Canada in 2005 and 2006. Mean parasitism rates of D. radicum puparia by A. bilineata ranged from 7.27% to 81.69%. Increasing proportions of wheat in intercrops significantly reduced parasitism by A. bilineata in one site-year. Parasitism of D. radicum by T. rapae was not affected by intercropping; mean parasitism rates were between 2.17% and 14.55%. In one site-year combined parasitism by all parasitoids significantly increased with increasing canola as a proportion of total crop plant populations. Pitfall trap collections of adult A. bilineata increased with increasing proportions of canola in some site-years. Collections of A. verna adults were low relative to A. bilineata and were largely unaffected by intercropping. Although canola-wheat intercrops do not appear to favour parasitism of D. radicum, reductions in canola root damage by Delia larvae in intercrops, reported previously, suggest that canola-wheat intercrops may nevertheless be favourable as a crop protection strategy.
  • Authors:
    • Lajeunesse, J.
    • Pageau, D.
    • Fregeau-Reid, J.
    • Collin, J.
    • Vanasse, A.
    • Lanoie, N.
    • Durand, J.
  • Source: Canadian Journal of Plant Science
  • Volume: 90
  • Issue: 3
  • Year: 2010
  • Summary: Naked oat ( Avena sativa L.) harvested in the province of Quebec, Canada, develops on average 10% covered grains and sometimes more. The objective of this study was to determine the effect of soil type, herbicides and their application stages on the proportion of covered grains in naked oat genotypes. Three genotypes were evaluated over 2 yr at two experimental sites. At each site, trials were seeded on two different soil types and each entry was treated with one of three types of herbicides: bromoxynil/MCPA, dicamba/MCPA and thifensulfuron methyl/tribenuron methyl, and compared with a weed-free check. The herbicides were applied at Zadoks 12-13 and 22-23. Results showed that dicamba/MCPA herbicide, applied at Zadoks 12-13, increased covered grains compared with the weed-free check and more covered grains were produced with the application made at Zadoks 22-23. However, differences in genotype reactions were observed. Few differences were found among the other weed control treatments. The application of dicamba/MCPA at Zadoks 22-23 decreased yield and test weight, but increased kernel weight. The other weed control treatments had no effect on agronomic characteristics.