• Authors:
    • Sirrine, J. R.
    • Simonson, P.
    • Hoagland, L. A.
    • Darby, H.
    • Benedict, C. A.
    • Turner, S. F.
    • Murphy, K. M.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 6
  • Year: 2011
  • Summary: Hop cones grown on the female plant of the perennial crop ( Humulus lupulus L.) are an integral component of the brewing process and provide flavor, bitterness, aroma, and antimicrobial properties to beer. Demand for organically grown hops from consumers via the brewing industry is on the rise; however, due to high N requirements and severe disease, weed, and arthropod pressures, hops are an extremely difficult crop to grow organically. Currently, the majority of the world's organic hops are grown in New Zealand, while other countries, including China, are beginning to increase organic hop production. Land under organic hop production in Washington State, where 75% of the hops in the United States are grown, increased from 1.6 ha to more than 26 ha from 2004 to 2010, and other hop-producing states demonstrate a similar trend. Removing hops from the USDA Organic Exemption list in January 2013 is expected to greatly increase organic hop demand and will require corresponding increases in organic hop hectarage. Current challenges, including weed management, fertility and irrigation management, insect and disease pressures, and novel practices that address these issues will be presented. Here, we discuss current and future research that will potentially impact organic hop production in the United States.
  • Authors:
    • Flaten, D. N.
    • Entz, M. H.
    • Vaisman, I.
    • Gulden, R. H.
  • Source: Agronomy Journal
  • Volume: 103
  • Issue: 3
  • Year: 2011
  • Summary: The blade roller offers new opportunities to reduce tillage, especially in organic farming. The objective of the study was to reduce tillage in the green manure phase of a green manure-wheat ( Triticum aestivum L.) rotation by substituting tillage with blade rolling. A pea ( Pisum sativum L.) and oat ( Avena sativa L.) green manure was used for two site-years at Carman, MB, while a pea monocrop was used for one site-year at Oxbow, SK. At pea flowering, the green manure was terminated by rolling, tilling, or a combination of the two. Ammonia emissions were greater in the no-till compared with the tilled green manure system, though total ammonia losses were low (<13 kg ha -1). Replacing tillage with rolling reduced soil nitrate N in autumn after green manure by 56 to 88 kg ha -1 in the 0- to 60-cm soil depth. Reduced green manure tillage did not affect wheat establishment but delayed plant development in some instances. Fewer weeds were often observed in wheat in the no-till compared with tilled plots. Total N supply in the green manure-wheat system was reduced in the no-till system compared to the tilled only system at two out of three site-years by an average of 44%. While reduced N supply in the reduced tillage system coincided with reduced wheat yield and protein, it was concluded that factors other than N also were involved. Using the blade roller instead of tillage in the green manure year provides soil conservation benefits and facilitates wheat production the following year.
  • Authors:
    • Lemke, R.
    • Frick, B.
    • Nagy, C. N.
    • Campbell, C. A.
    • Ulrich, D.
    • Thomas, A. G.
    • Brandt, S. A.
    • Basnyat, P.
    • Zentner, R. P.
    • Malhi, S. S.
    • Olfert, O. O.
    • Fernandez, M. R.
  • Source: Renewable Agriculture and Food Systems
  • Volume: 26
  • Issue: 3
  • Year: 2011
  • Summary: Producers in the semi-arid Dark Brown Chernozemic (Typic Boroll) soil zone of the Canadian Prairie are contemplating changes to land-use practices, moving away from conventional high-input production systems that specialize in one or two annual grain crops to more diversified and extended cropping systems that use reduced-input and organic management practices. This study examined the economic merits of nine cropping systems, consisting of a factorial combination of three input management methods and three levels of cropping diversity. It was conducted over the 1996-2007 period on a loam soil at Scott, Saskatchewan. The input treatments were: (1) high input (HIGH), which used conventional tillage and full recommended rates of fertilizers and pesticides 'as required'; (2) reduced input (RED), which used conservation tillage and integrated weed and nutrient management practices in an effort to lower requirements for fuel, fertilizers and pesticides; and (3) organic input (ORG), which used tillage, non-chemical pest control, higher seeding rates, delayed seeding and legume crops to replenish soil nutrients. The crop diversity treatments included: (1) a fallow-based rotation with low crop diversity (LOW); (2) a diversified annual rotation of cereal, oilseed and pulse grains (DAG); and (3) a diversified rotation using annual grains and perennial forages (DAP). All crop rotations were 6 years in length. At the 2007 input costs and prices, average net returns and 12-year net present values were higher for organic than for non-organic treatments, with the ORG input/LOW crop diversity system being the most profitable (net returns=$234 ha -1 yr -1 and net present value=$1953 ha -1). Net returns averaged about 10% less for ORG/DAG compared to the most profitable system, and about 22% less for HIGH/DAG and RED/DAG (the best non-organic systems). The DAP treatments that included forage were not economically competitive with the other treatments, often producing economic losses. The relative profitability of the organic treatments was highly dependent on the existence of organic price premiums. When price premiums for organic crops were reduced to less than 70% of the 2007 levels, the organic treatments were less profitable than the comparable non-organic treatments. The organic treatments also experienced significantly lower (and often negative) net returns compared to the non-organic treatments during completion of the 3-year organic certification period. We estimated that it required 5-7 years after completion of certification for the organic treatments to break even with the comparable non-organic treatments. Thereafter the organic treatments produced consistently higher net earnings. Production costs averaged 16% lower with ORG management compared to the HIGH-input treatments, but we found little difference in total costs between the respective HIGH- and RED-input treatments. The organic treatments also displayed lower income variability than the non-organic treatments, with the ORG/LOW system being preferred by risk-averse producers, who do not subscribe to all-risk crop insurance, and with the ORG/LOW and ORG/DAG systems preferred by low and medium risk-averse producers when having the added financial protection from the Canada/Saskatchewan all-risk crop insurance program.
  • Authors:
    • Zekaite, V.
    • Deveikyte, I.
    • Kadziuliene, Z.
    • Sarunaite, L.
    • Maiksteniene, S.
    • Arlauskiene, A.
    • Cesnuleviciene, R.
  • Source: ZEMDIRBYSTE-AGRICULTURE
  • Volume: 98
  • Issue: 4
  • Year: 2011
  • Summary: Intercropping of cereals and grain legumes is a technology intended to enhance biodiversity in organic agroecosystems, increase and stabilize yields and make better use of plant growth resources. The experiments were designed to investigate the intercrops' yield advantage in different soil, climate and plant competition conditions in organic farming. Field trials were carried out during 2007-2010 at the Lithuanian Institute of Agriculture at three different soil sites: on a loamy Endocalcari-Epihypogleyic Cambisol ( CMg-p-w-can) (Dotnuva), on a clay loam Endocalcari-Endohypogleyic Cambisol ( CMg-n-w-can) (Joniskelis) and on a sandy loam Hapli-Albic Luvisol ( LVe-ha) (Perloja). Pea ( Pisum sativum L. (Partim)) and spring wheat ( Triticum aestivum L. emend. Fiori et Paol.), spring barley ( Hordeum vulgare L.), oat ( Avena sativa L.) and spring triticale (* Triticosecale Wittm.) were sown as intercrops (50:50 - a relative proportion of grain legume and spring cereal seeds) or as a sole crop. The result showed that weather and soil conditions during plant emerge determined the optimal productive density and created a basis for competition between the intercrop components. Spring cereals were dominant due to higher aggressivity index and competition rate compared with peas. Under various soils' conditions the aggressivity of cereals increased with increasing density of pea. In productive soils (Dotnuva, Joniskelis), the highest competitive and suppressive power in the intercrops was exhibited by oats, in low productivity soils (Perloja) - the dominant species varied. Under the conditions of various soils, the production of pea intercrop with oats or barley was directly affected by cereals, while pea intercropped with wheat or triticale by the two components of the intercrop. In terms of grain yield, intercrops ranked as follows: pea/oats > pea/wheat, pea/triticale > pea/barley. In loamy soil (Dotnuva), these regularities were less consistent, therefore the advantages of intercrops' yield over sole crops' yield were negligible when the relative yield total (RYT) was >1.0, except for the pea intercropped with barley. In Joniskelis and Perloja, the relative yield total showed greater and more stable yield advantages of intercrops, except pea intercropped with triticale. The efficiency of intercrops stood out even more vividly in the treatments managed under organic cropping system for a longer period of time.
  • Authors:
    • Emeran, A. A.
    • Shtaya, M. J. Y.
    • Fernandez-Aparicio, M.
    • Allagui, M. B.
    • Kharrat, M.
    • Rubiales, D.
  • Source: Crop Protection
  • Volume: 30
  • Issue: 8
  • Year: 2011
  • Summary: Chocolate spot incited by Botrytis fabae is a serious faba bean disease of worldwide distribution. The increasing interest in sustainable tools for disease control, together with the lack of sufficient levels of genetic resistance triggered our interest in the use of intercropping as a tool for the management of this disease. The effect of intercropping on chocolate spot severity was studied in field experiments performed in Egypt, the Palestinian Territories, Spain and Tunisia, in which a susceptible faba bean cultivar was grown as a monocrop or with two mixed species intercrops of either barley, oat, triticale, wheat, pea or common vetch, or with three mixed species intercrops of wheat and berseem clover. Chocolate spot was significantly reduced when faba bean was intercropped with cereals, but not when intercropped with legumes. Suppressive effects can be ascribed to a combination of host biomass reduction, altered microclimate and physical barriers to spore dispersal.
  • Authors:
    • Leap, J.
    • Klonsky, K. M.
    • Shennan, C.
    • Smith, R. F.
    • Muramoto, J.
    • Ruiz, M. S.
    • Gliessman, S. R.
  • Source: HortScience
  • Volume: 46
  • Issue: 8
  • Year: 2011
  • Summary: Legume/cereal mixed winter cover crops are commonly used by organic growers on the central coast of California, but they are unable to provide sufficient nitrogen (N) for a high N-demanding vegetable crop such as broccoli and supplemental fertilizer application may be necessary. The goals of this project were to evaluate the contribution of N from a mixed legume/cereal cover crop (CC) and feather meal and blood meal as organic fertilizers (OF) to an organic broccoli crop and to evaluate economic benefits of CC and OF to the subsequent organic broccoli crop. Trials were conducted at two sites (A and B) with different management histories. Cover crops were grown over the winter and incorporated into the soil in the spring and subsequently broccoli [ Brassica oleracea L. (Italica group)] was grown in 2006 at both sites and in 2007 at B only. Cover crop and no CC treatments were grown with supplemental organic fertilizers at four fertility levels (0, 84, 168, and 252 kg N/ha of OF) with four replicates. Generally broccoli head yields at A (14.9 to 26.3 Mg.ha -1) were higher than at B (0.7 to 17.4 Mg.ha -1 in 2006 and 5.5 to 17.9 Mg.ha -1 in 2007). Yield and aboveground biomass N were significantly increased by OF at rates up to 168 kg N/ha at A and to 252 kg N/ha at B and by CC in 2006 at both sites but not in 2007 at B. Although N content of the CC was similarly low at A (2006) and at B (2007), immobilization of soil mineral N occurred only at B. This suggests that the addition of a low N content CC was offset by high N mineralization from the soil at A with a long organic management history (greater than 33 years). Supplemental fertilizer applications may be necessary to achieve optimal yields, but the amount needed can be reduced by cover cropping in fields with a long history of cover crop-based organic management (A) or when cover crop N content is sufficiently high to prevent immobilization (B, 2006). Soil NO 3-N patterns suggest a pre-side dress nitrate test may also be useful for N management in organic broccoli. Use of cover crops increased net return above harvest and fertility costs when the yield reduction by N immobilization did not take place. However, the net return increase by the use of cover crops tended to diminish as the rate of OF application increased.
  • Authors:
    • Hermansen, J.
    • Panneerselvam, P.
    • Halberg, N.
  • Source: Journal of Sustainable Agriculture
  • Volume: 35
  • Issue: 1
  • Year: 2011
  • Summary: This study compared farm production, crop yield, input cost, and income in organic and conventional farming systems in three states of India: Uttarakhand, Madhya Pradesh, and Tamil Nadu. The results showed that organic farming reduced the input cost without affecting the net margin in all three states. Total food production was found to be comparable for the two systems in two of three states. While yield of rice and wheat generally was lower under the organic systems, yield from intercropping food crops was generally higher. The number of agro-ecological methods and percentage of farms practicing different agro-ecological methods were higher under organic systems than conventional systems. These results suggest that organic farming has the potential to improve food security of small farmers by reducing indebtedness due to the lower cost of production without affecting total farm production and farm income.
  • Authors:
    • Ponizil, A.
    • Henriksen, B.
    • Pozdisek, J.
    • Loes, A. K.
  • Source: Agronomy Research
  • Volume: 9
  • Issue: 1/2
  • Year: 2011
  • Summary: In 2009, controlled field trials were conducted on three certified organic farms with field pea (leaf type), spring barley and spring wheat in monocultures and mixtures (pea:cereal ratio 60:40) to study the possibility of producing fodder for monogastric animals under Czech conditions. By grain harvest time, seed samples were collected and analysed for dry matter, ash, crude protein, fat and crude fiber, and content of organic matter and nitrogen-free extracts (NFE) were determined. Weed harrowing at various pea heights were included at one farm. Samples for analysis of tannins and trypsin-inhibitor activity (TIA) were taken from treatments with no weed harrowing (H0) and harrowings at 5 and 10 cm pea height (H2). Analyses of amino acids were conducted from H0-samples. To complement the data from the farm trials, samples of grains from treatments with the same pea and cereal varieties in plot trials conducted in 2008 and 2009 studying the effect of pea:cereal seed ratio and weed harrowing at various pea heights, were analysed. In cereals, the crude protein content increased by intercropping with pea. This increase was compensated for by a decrease in NFE. Wheat and barley grown in mixtures with peas seemed to contain more methionine than cereals in monoculture, and there tends to be higher threonine content in intercropped barley compared with barley monoculture. This is positive for the nutrition of monogastric animals. There were no pronounced effects of intercropping on tannins or TIA or on the content of other analysed nutrients in the cereals. The chemical composition of peas was not significantly impacted by intercropping.
  • Authors:
    • Ichiyama, K.
    • Jitsuyama, Y.
    • Iwama, K.
    • Uchino, H.
    • Sugiura, E.
    • Yudate, T.
  • Source: Plant Production Science
  • Volume: 14
  • Issue: 1
  • Year: 2011
  • Summary: The use of cover crops is an effective technique to control weeds, which are one of the most serious problems for crop production without using herbicides. This study investigated the characteristics of cover crops for weed suppression at an organic farming field in a snowy-cold region, Hokkaido. Nine, three and two species of cover crops comprising both Poaceae and Leguminosae were grown in 2003, 2004 and 2005, respectively, at different sowing densities from 50 to approximately 4000 seeds m -2. The relationships between weed dry matter production and characteristics of cover crops, such as plant height and coverage, were investigated at 4 and 10 weeks after cover crop sowing (WAS). Correlation analysis of the weed dry weight with characteristics of cover crops revealed that the cover crop coverage at 4 WAS had a strong and stable effect on weed suppression. The cover crop coverage at 4 WAS was affected primarily by their seed weight when cover crops with a large variation in seed weight were used, and by the sowing density when cover crops with a small variation in seed weight were used. These results suggest that to achieve high weed suppression it is important to obtain higher coverage at the early growth stage of the cover crops with a heavy seed weight and high sowing density.
  • Authors:
    • Rychcik, B.
    • Wachowska, U.
    • Kurek, K.
  • Source: Progress in Plant Protection
  • Volume: 51
  • Issue: 2
  • Year: 2011
  • Summary: The health status of flag leaves and stem bases of hulled oats cv. Chwat grown in the ecological and conventional systems was determined in a field experiment conducted in 2008-2010. The soccurrence of leaf diseases was low. Leaf spots caused by Pyrenophora avenae and Stagonospora avenae covered up to 6% flag leaf area. The applied farming systems had no significant effect on the health status of the flag leaves and stem bases of hulled oat. More numerous colonies communities of Azotobacter and Pseudomonas bacteria and yeast-like fungi were isolated from the grain of hulled oat grown in the conventional system, as compared with the ecological system. Alternaria alternata was the predominant species among the of filamentous fungi. Colonies of pathogens of the genus Fusarium and the species Bipolaris sorokiniana were also isolated. Filamentous fungi, including B. sorokiniana, tended to colonize oats kernels in the ecological farming system.