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• Green manures are recommended for organic management of plants in high tunnel. • Rotary tillage, especially with fresh biomass mulch, has a positive effect on the yield of vegetable plants in high tunnel. • Ambiguous effect of green manures on the chemical composition of edible parts of vegetables was observed. Tunnel production is well suited to growing high-value crops, such as organic vegetables or fruits. Effects of cover crops integration into crop rotations were evaluated in an organic system in a high tunnel. In the research conducted at the Experimental Station of the University of Agriculture in Krakow, turnip and swede (rutabaga) sown in 2018, and phacelia and buckwheat, sown in 2020 in the second cycle, were used as green manure. The vegetable crop rotation included successive cultivation of pumpkin, romaine lettuce, broad bean, hot pepper (2018–2019), and leek and leaf parsley (2020–2021). The control was a plot without plants sown for green manure, covered with black polyethylene film during their cultivation. The effect of green manures on yielding and chemical composition of edible parts of vegetable plants was studied. The beneficial effect of turnip and swede was noticeable only in the autumn cultivation of romaine lettuce. The obtained yield was 63,3 % average higher. The significant effect on the yield of early broad bean was also shown. Grain yield was with 90,9 % higher in case of turnip and higher with 59,1 % in case of rutabaga than in the control plot. This trend was also observed in the cultivation of hot pepper. Its yield after rutabaga was with 189 % higher, and it was 102 % as high after the preceding crop of turnip compared to the control. Whole-plant of leeks yield, was higher (15,8 %) on the phacelia treatment in comparison with control. The total yield of parsley leaves was significantly higher in the plot following phacelia and buckwheat compared to the control (197 % in average). In general, the chemical composition evaluation did not find a clear impact of green manures. However, leeks grown in the control plot had the highest dry matter and vitamin C content. [ABSTRACT FROM AUTHOR]

Annual rotation green manure crops of selected brassicas, buckwheat, forage pearl millet, forage radish, black-eyed Susan, sesame, sudangrass, and velvetbean were evaluated to determine impacts on lesion nematode Pratylenchus penetrans and dagger nematode Xiphinema americanum populations densities. Canadian forage pearl millet ' 101'and 'Tifgrain 102' millet effectively controlled P. penetrans but increased population densities ofX. americanum. Black-eyed Susan (Rudbeckia hirta) and sudangrass 'Trudan 8' also reduced P. penetrans densites but notX. americanum. Rapeseed and other brassicas as a green manure reducedX. americanum densities but did not suppress P. penetrans. Brassica juncea 'Pacific Gold', B. napus 'Dwarf Essex', but not mustard 'Caliente' resulted in low densities ofX. americanum in soil. Velvetbean and sesame increased both P. penetrans and X. americanum population densities. A moderately suitable host plant such as buckwheat was ineffective in managing both P. penetrans and X. americanum populations. These results emphasize that suppressive effects of any given cover crop are nematode-specific, and that within a group of cover crops, e.g., the Brassicaceae, species and varieties can vary substantially in their effectiveness. If the rotation crop chosen is a good host for the nematodes present, it may exacerbate the problem instead of controlling it. [ABSTRACT FROM AUTHOR]

Weeds are the component of biological diversity in the agricultural systems (agrobiodiversity) and one of the greatest limiting factors to efficient organic crop production. The goal of the experiment is to define the influence of organic agricultural practices on the dynamics of weed infestation, weed species diversity and community composition in organic potato field included in three-field crop rotation. The results show that all analyzed weed parameters are characterized by high dynamics during potato grown seasons. The biological development of weeds in the cover crop before incorporation to the potato field was strongly limited. According to the data obtained, cover crop for green manure and mechanical soil tillage in the organic potato field were effective practices for controlling the weed infestation. The effect of organic practices on the weed community parameters were assessed by ecological indexes (Shannon index (H'), Shannon-Wiener evenness index (J'), index of dominance (Simpson dominance index, D) and similarity indexes (Srensen similarity index, SSI). Results show that the studied three-field crop rotation included winter wheat, green bean, peas and rye mixture as cover crops and potato is a strategic scheme for achieving good weed control at the end of the rotation. The comparison of similarity of weed communities in a potato field between 2012 and 2013 using Srensen indices shows that the similarity was higher on the base of the qualitative index (35.3%) than of the quantitative ones (20.8%). [ABSTRACT FROM AUTHOR]

Many factors are driving interest in improving soil health in potato production systems in the U.S. Pacific Northwest and beyond, including the need for enhanced sustainability and economic viability, and consumer preferences. Potato production poses a particular challenge in terms of soil health due to intensive tillage, minimal residue left on fields, short rotations, and the importance of managing soilborne pathogens. This review discusses existing soil health assessment methods and their relevance for the region and summarizes results of studies conducted in the Pacific Northwest and beyond, examining practices aimed at improving soil health and their effects on soil health, soilborne pathogens, yield and quality of potatoes, and net returns in potato production systems. These practices include reducing tillage; adjusting crop rotation length and species composition; reducing fumigation; and using cover crops, green manures, and organic amendments. [ABSTRACT FROM AUTHOR]

The aim of this study was to identify the cutting time for winter cover crops used as green manure in no-tillage systems that results in the highest dry weight yield (DWY) and nutrient accumulation. We testedAvena strigosa, Secale cereale, Vicia sativa, Raphanus sativus, andLupinus albus, in five management times, determining the fresh weight yield (FWY), DWY, and the chemical composition of the shoot tissue. The highest FWY was obtained usingR. sativusandL. albus. At 145 days after sowing; these species also had the highest DWYs, over 15 t ha−1.L. albusandS. cerealehad the highest carbon to nitrogen (C:N) ratio (60:1). The nutrient content of most crops decreased over time. However, the accumulation of nutrients increased over time, especially forR. sativus. L. albushad the highest level and manganese (Mn) accumulation, while the zinc (Zn) and cooper (Cu) accumulation was highest inA. strigosa, and that of boron (B) was highest inS. cereale. Thus,R. sativusprovided the best soil cover among the species tested, due to its high biomass yield and greater nutrient cycling. [ABSTRACT FROM AUTHOR]

Abstract: To address the decline in crop productivity in the drylands of West Africa, many initiatives have focused on combating soil degradation. Various practices including (1) parkland trees associated with crops, (2) coppicing trees, (3) green manure, (4) mulching, (5) crop rotation and intercropping, and (6) traditional soil/water conservation have been tested. The present study attempts to provide a comprehensive, quantitative synthesis of existing reports on the effect of conservation agriculture (CA) practices on crop yield response in Burkina Faso, Mali, Niger and Senegal. Out of a total of 155 reports found, 63 fulfilled all the appropriate criteria to be included in the meta-analysis of the effect of various conservation agriculture practices on the yield response of maize, millet and sorghum. The study revealed significant variability in cereal yield response (and hence risk) with all the practices examined. Despite the variability, the mean effects of the six CA practices on crop yield were more positive than negative except with parkland trees. However, for this last practice, species like Faidherbia albida exerts more positive impact on crop yield. Yield increases relative to the control were higher with green manure and mulching than with coppicing trees and parklands. Increases in yield in the six CA practices were higher on low to medium productivity sites for maize, millet and sorghum. Coppicing trees and rotations improved yields when the rainfall is >800 mm whereas the opposite happens with parkland and soil–water conservation measures. Mulching performed better when the rainfall is <600 mm. The variability (and hence yield risks) calls for more understanding of the processes and application of appropriate tree management to reduce crop yield losses while still providing products (fruits, leaves, wood, etc.) and services (soil carbon building up) for long-term sustainability of the production systems in drylands of West Africa. [Copyright &y& Elsevier]

• Whole-year leguminous green manure crops can reduce the weed seed bank in subsequent crops. • Weed seed bank reduction may reach 65 % at the time of termination of a green manure crop. • The legacy effect on the seed bank is still substantial three years after termination. • Periods with green manure crops can be important for the management of soil fertility and weeds in organic cropping systems. Leguminous green manure crops are important for accumulating nitrogen by means of biological nitrogen fixation and for building up soil fertility in organic arable cropping systems. Whole-year green manure crops are also known to deplete the soil weed seed bank, e.g. by decaying and predation, but there is uncertainty about the magnitude of the legacy effect after termination of the green manure crop. This study sampled soil for weed seed bank assessment upon termination of a two-year leguminous green manure crop and then one, two and three years afterwards. The samples were taken from two five-year crop rotations (2011–2015) in a long-term organic crop rotation experiment in Denmark. One rotation (O2) had a two-year green manure crop followed by three years of annual cash crops, and the other rotation (O4) consisted only of annual cash crops, with four crop sequences in both rotations represented every year. In general, the weed seed bank of rotation O2 was 54 % lower than O4, with 5475 seeds m−2 versus 11,967 seeds m−2. Similarly the aboveground amount of weed biomass in O2 was lower than in O4 over the course of the five years. The legacy effect of the green manure crop showed a negative exponential rise in weed seed numbers with the increase in years after termination of the green manure crop. A biennial leguminous green manure crop can mitigate weed problems in organic annual crops. This effect adds to the benefits of including nitrogen fixing leys in crop rotations with limited access to animal manures. [ABSTRACT FROM AUTHOR]

Sustainability of agricultural practices is one of the most important issues in organic agriculture and its assessment is crucial. To this aim, evaluating the balance between the energy inputs and outputs in crop rotations could be a valuable tool. Therefore, we compared different management strategies in a four-year organic cropping system, by estimating the energy balance of crop production. Two different living mulches with no-till (B1) and green manure (B2) were compared with a cropping system without cover crop (B3), performing both energy analysis and energy balance. Energy parameters were also evaluated. The energy input of fertilizers and water was more than 55% of the total energy required by the cropping systems, suggesting that these agronomic practices should be tailored by farmers to decrease total energy inputs. The potential energy output was significantly higher in the B1 than the B2 and B3 cropping systems (20% and 54%, respectively). Results indicated that B1 and B2 could enhance the energy outputs without negatively affecting the energy consumption, since these cropping systems also showed higher energy efficiency. The introduction of the cover crop as living mulch combined with no-till could be a powerful tool to enhance systems sustainability, without compromising the crop yields. [ABSTRACT FROM AUTHOR]