Legume Mixtures Research Articles

Winter cover crops influence Amaranthus palmeri establishment

Winter cover crops were evaluated for their effect on Amaranthus palmeri establishment and growth in cotton production. Cover crops examined included rye and four winter legumes: narrow-leaf lupine, crimson clover, Austrian winter pea, and cahaba vetch. Each legume was evaluated alone and in a mixture with rye. Cover crop biomass in monoculture was greatest for rye and lupine (>6750 kg ha−1), while clover, pea, and vetch were less and ranged from 2810 to 4610 kg ha−1. Cover crop biomass was more than doubled when rye was mixed with clover or vetch relative to the legume monoculture. In early-June, A. palmeri densities were 46 seedlings m−2 in the non-disturbed areas between cotton rows in the fallow, while populations were <4 seedlings m−2 with rolled vetch or pea and 18 and 29 seedlings m−2 in rolled clover and lupine. Rye and legume mixtures reduced A. palmeri densities to <3 seedlings m−2, while rye monocultures had 8 seedlings m−2. There were no differences in A. palmeri densities (≥144 plants m−2) in the cotton row among cover crop treatments. By late-June, rye and winter pea controlled A. palmeri in the row middle >80% relative to the non-cover crop fallow treatment, while control from clover, vetch and lupine ranged from 64 to 70%. The relationship between A. palmeri control in between cotton rows and cover crop biomass was described by a log-logistic regression model with 4530 kg ha−1 providing median weed control (Bio50); predicted A. palmeri control was 25, 50, and 75% from 2950, 4900, and 8600 kg ha−1 cover crop biomass, respectively. However, A. palmeri plants in the cotton rows prevented yield production in the absence of herbicides. Where A. palmeri was controlled with herbicides, the highest yields occurred following rye, with lower yields following lupin/rye mixture and treatments including pea. Management of herbicide resistant weed species requires diverse management tactics; this may include high-biomass cover crops to reduce weed establishment between crop rows. However, greater research effort is needed to devise weed management options for the crop row that do not rely exclusively on the diminishing array of herbicide tools.

Forage yield, quality and economic benefit of intercropped barley and annual medic in semi-arid conditions: Additive series

Production of high-yielding quality forage remains a challenge in arid and semi-arid conditions. Cereal–legume mixture may be a viable option to improve forage yield and increase on-farm protein production. A two-year experiment was conducted in 2009 and 2010 to determine if mixtures of barley (Hordeum vulgare L.) and annual medic (Medicago scutellata L.) could increase forage quality and forage dry matter. A randomized complete block design with two additive intercropping systems (100B:20M) (100% of barley pure stand seeding rate with 20% of annual medic pure stand seeding rate) and (100B:40M) with sole cultures of barley and annual medic. Total dry matter yield produced by intercrops averaged 3385kgha−1 and was similar to that of barley sole crop (3590kgha−1). The land equivalent ratio was highest (1.07) when barley was intercropped with annual medic in the 100B:40M intercrop indicating that 7% more area would be required by a sole cropping system to produce a similar yield. Based on results from LER, relative crowding coefficient (RCC) and monetary advantage index (MAI), it was concluded that 100B:40M was superior to either barley or annual medic monocropping. The highest protein yield (893kgha−1) was obtained from the 100B:40M intercrop. When both forage yield and quality were considered, the 100B:40M intercropping system was superior and could be recommended as an alternative to barley alone.

Grasses and legumes in mixture: an energy intercropping system intended for anaerobic digestion

Batch testing of biomethanization was conducted on organic matrices from a mixture of grasses (triticale and barley) and legumes (field bean - Vicia faba L. var . minor ). These tests were performed in mesophylic conditions (35°C) on previously chopped and ensiled biomass. The three crops have been cultivated in Southern Italy (Puglia region), both as single-crops and intercropping between triticale or barley and field bean, in different mixture combinations, during the season 2009-2010. Emphasis was placed on the determination of the chemical composition of feedstock from the three single species and their different intercropping ratios, mowed at two subsequent stages (milk and dough development of grasses), also assessing their consequent biogas and methane potential yields after silage. Seven overall treatments have been compared: the three species in monoculture (triticale, barley and field bean, respectively); two mixtures between triticale and field bean (with triticale at 70 and 50%, respectively); two mixtures between barley and field bean (again with barley at 70 and 50%, respectively). Immediately after cutting and for the next 90 days, biomass samples were closed into plastic mini-silos, each having a 5-L capacity, in order to simulate the silage process. Thereafter, the batch testing was performed and biogas and methane production have been determined, with respect to the main chemical characteristics of the chopped and ensiled biomass samples, able to affect biogas and methane yield. Considering the single-crop treatments the highest biogas per hectare production has been found with respect to triticale (8737.1 nm 3 ha -1 ) and barley (8837.6 nm 3 ha -1 ), at the first and second harvesting stage, respectively. Concerning grass-legume intercropping, the highest biogas yield (8635.0 nm 3 ha -1 ) was observed with reference to the 70:30 mixing ratio, specifically on barley mowed at the milk development stage. The methane content in the biogas ranged from 61.1% (on a 50:50 mixing ratio of barley at the milk stage) to 53.7% (on a barley monoculture at the dough stage).

Benefits of mixing grasses and legumes for herbage yield and nutritive value inNorthernEurope andCanada

AbstractIncreased biodiversity may improve ecosystem services, including herbage yield. A mixture experiment was carried out at five sites inNorthernEurope and one inCanada to investigate whether mixtures of grasses and legumes would give higher herbage yield than monocultures. Resistance of the mixtures to weed invasion and nutritive value of the herbage were also investigated. The experimental layout followed a simplex design, where four species differing in specific functional traits, timothy (Phleum pratenseL.), smooth meadow grass (Poa pratensisL.), red clover (Trifolium pratenseL.) and white clover (Trifolium repensL.), were grown in monocultures and eleven different mixtures with systematically varying proportions of the four species. Positive diversity effects (DE) were observed, leading to greater herbage dry‐matter (DM) yield in mixtures than expected from species sown in monocultures. For centroid mixtures, theDEgenerated on average an additional 32, 25 and 21% of theDMyield than would be expected from the monocultures in the first, second and third year respectively. On average, the mixtures were 9, 15 and 7% more productive than the most productive monoculture (transgressive overyielding) in the first, second and third year respectively. These benefits persisted over the three harvest years of the experiment and were consistent among most sites. This positive effect was not accompanied by a reduction in herbage digestibility and crude protein concentration that is usually observed with increasedDMyield. Mixtures also reduced the invasion of weeds to &lt;5% of herbage yield compared to monocultures (10–60% of herbage yield).

Growth and Nutritive Value of Three Old World Bluestems and Three Legumes in the Semiarid Texas High Plains

Benefits of legume–grass mixtures are well known but water required for legume growth limits use in semiarid, irrigation‐dependent environments. Research conducted over 4 yr (2007 to 2010) in the semiarid Texas High Plains compared alfalfa (Medicago sativa L.), yellow sweetclover [Melilotus officinalis (L.) Lam.], and sainfoin (Onobrychis viciifolia Scop.) interseeded into three old world bluestems (Bothriochloa spp.). No fertilizer N (control) and 60 kg N ha−1 treatments were applied to grasses alone. The five treatments imposed on each grass were replicated three times in a randomized complete block design with the legume and N treatments in a split‐plot arrangement. Irrigation water applied through subsurface drip was limited to 250 mm annually. Annual dry matter yield of grass monocultures exceeded grass–legume mixtures in year 1 but yield of grass–legume mixtures was similar to N fertilizer in subsequent years. Crude protein (CP) and dry matter digestibility (DMD) were higher while cell wall was lower in the mean of grass–legume mixtures than grass monocultures. Nitrogen fertilization increased CP but had little effect on cell wall or DMD (g kg−1). Nutritive value benefits from yellow sweetclover occurred in year 1 and then declined while benefits from alfalfa increased over 4 yr. Lower sainfoin stands limited nutritive value. With limited irrigation, benefits of including legumes can exceed 60 kg N ha−1 in this semiarid environment.

INFLUENCE OF SOWING PERIOD ON THE FORAGE PRODUCTIVITY AND WEED INFESTATION OF ANNUAL WINTER CEREAL AND LEGUME CROP

During the 2011–2012 period in the Research Institute of Mountain Stockbreeding and Agriculture (RIMSA) in Troyan (Bulgaria) the effect of sowing time on some bio–productive indicators (green mass and dry matter yields, weed infestation) of the forage from annual winter cereal and legume mixture of winter barley and winter pea was performed. As variants the following sowing periods carried out during 10 days were studied: 1. 20–30 September (Standard); 2. 1– 10 October; 3. 11–20 October; 4. 21–30 October. It was established that the most optimal time for sowing of mixed crop grown under foothill conditions of the Central Balkan Mountains (Troyan region) is the period from 1 to 20 October. The received forage amounted to 2.38 t.ha green mass and 0.59 t.ha dry mass, which exceeded the standard sowing period (20–30 September) with 25.26% and 59.46%, respectively. Irrespective of the autumn sowing period, weed infestation of the crop of winter cereal–legume mixture was comparatively low, ranging from 0.74 to 4.88%.

CHANGES OF SOME FORAGE INDICATORS DEPENDING ON SOWING PERIOD OF ANNUAL LATE–SPRING CEREAL AND LEGUME CROP

During the 2010–2012 period in the Research Institute of Mountain Stockbreeding and Agriculture (RIMSA) in Troyan (Bulgaria) the effect of sowing time on some bio–productive indicators (green mass and dry matter yields, weed infestation) of the forage from annual late– spring cereal and legume mixture from maize and white lupine was performed. As variants the following periods of sowing (during 10 days) were studied: 1. 10–20 April (Standard); 2. 21–30 April; 3. 1–10 May; 4. 11–20 May. The most optimal sowing time of annual late–spring mixed crop from maize and white lupine grown under foothill conditions of the Central Balkan Mountains (Troyan region) is the period from 10 to 20 April. The received forage amounted to 2.53 t.ha green mass and 0.39 t.ha dry matter; while in the others later periods the yields were relatively low. A less weed infestation of the mixed crop was reported at the earlier periods of sowing.

FORAGE PRODUCTIVITY AND WEED INFESTATION OF ANNUAL EARLY–SPRING MIXTURE UNDER DIFFERENT SOWING DATES

During the 2011–2012 periods in the Research Institute of Mountain Stockbreeding and Agriculture (RIMSA) in Troyan (Bulgaria) the effect of sowing time on some bio– productive indicators (green mass and dry matter yields, weed infestation) of the forage from annual early–spring cereal–legume mixture from oats and field pea was performed. As variants the following periods of sowing were studied: 1. 10–20 March (Standard); 2. 21–30 March; 3. 1– 10 April; 4. 11–20 April. It was established that the optimum time for sowing of annual early spring pea and spring oats mixed crop was the period from 10 to 20 March. Then was received most plant production (1.84 t.ha green mass and 0.41 t.ha dry matter), which exceeded the other sowing periods from 7.07% (21–30 March) to 27.72% (11–20 April) and from 1.6 to 8.13%, respectively. In the different sowing times the weed infestation of crops varied and was a highest in early spring sowing (10–20 March)–from 8.40 to 9.26%.

Silvipastoral approach to improve productivity of native pastures for improved livestock production in mid hills of Western Himalaya

Animal husbandry, an integrated component of hill agriculture has caused severe land degradation due to continuous grazing and massive reduction in the vegetation cover. The feeding of livestock depends primarily on natural resources, viz. grasslands, forests, cultivated fodder, field bunds, crop residues, weeds and fodder trees. The silvipasture laid out at 3 sites, viz. Ghanetta (1100 m above msl), Dagoh (1020 m above msl) in Kangra district and Jogindernagar (1175 m above msl) in Mandi district of Himachal Pradesh had a slope of 15–35%, 25–60% and 15–30%, respectively. Silipastures were laid out with active participation of native beneficiaries. Survival rate of Bauhinia variegata, Morus alba and Grewia optiva was highest (90% and above) at all the 3 sites. Growth in terms of height gained by the fodder trees was similar at all the 3 sites. At the end of third year, the 2- year-old saplings transplanted at all the 3 sites, Albizia attained a height of about 200 cm, Artocarpus (110 cm), Bauhinia (150 cm), Grewia (120 cm) and Morus (130 cm). During third year of the study fresh biomass of 31.6, 28.6 and 30.8 t/ha were harvested from Ghanetta, Jogindernagar and Dagoh with dry matter yield of 8.67, 6.98 and 7.62 t/ha, respectively. Crude protein was in the range of 12.33 to 13.46% due to grass legume mixture. The average body weight gain ranged from 358.50 to 388.53 g/day in indigenous male cattle. Runoff (% of rainfall) was higher at Jogindernagar (33.4%) followed by Dagoh (29.9%) and Ghanetta (20.4%) owing to their land slopes. Cut and carry system was most efficient at all the sites allowing only 15.8% runoff compared to 20.6% and 27.1%, respectively under controlled and traditional grazing. Among the resource conservation measures, trenching in combination with vegetative barrier allowed only 6.8% of rain as runoff compared to 38.9% under control (no measure). Trenches formed in upper, middle and lower parts along the slope retained on an average 13.9, 16.6 and 19.1 cm sediments, respectively. Among the sites, the sediment retention was highest at Dagoh (18.7 cm) followed by Joginder Nagar (16.9%) and lowest at Ghanetta (14.0 cm). Therefore, silvipasture seems to be one of the best options for regenerating and improving the Himalayan grasslands. The system can enhance the forage availability many fold, which can assure the sustainability of on-going livestock rearing and in the process the resource base gets conducive inputs for its conservation.

Grazing Behavior of Steers on Different Annual Ryegrass and White Clover Forage Systems

ABSTRACTStudying grazing behavior of ruminants may help increase the understanding of the use of forage systems of varying forage types and composition. This study was conducted during 2008 at Raymond, MS, to evaluate grazing time by ruminants on various forage systems to examine any relationship with pasture composition and stocking rate (SR). Annual ryegrass (Lolium multiflorum Lam. ‘Marshall’) and white clover (Trifolium repens L. ‘Durana’) were used to create forage system treatments of either monoculture grass (MG) or monoculture legume (ML), a binary mixture of grass and legume (MIX), or a spatial system of adjacent grass and legume monocultures in a 50:50 land area ratio within the same paddock (SS). Two levels of SR (3 or 6 steers [Bos taurus] ha−1) were imposed on each of the four forage systems to give a 4 × 2 factorial arrangement of treatments with two replicate paddocks of each treatment combination in a completely randomized design experiment. Two Angus crossbred yearling beef steers (236 ± 24 kg initial body weight [BW]) were randomly assigned to each of the 16 paddocks. Time spent grazing per animal on continuously stocked pastures was recorded for 10 d selected randomly during the months of April and May, with each day of observation lasting for 14 h (0615 to 2015 h). Forage system had an effect (P &lt; 0.001) on time spent grazing daily. Animals grazing MG and MIX spent similar time grazing (mean = 442 min per animal), which was greater than daily grazing time on SS (380 min per animal). Grazing time was least on ML (341 min per animal). Also, SR had an effect (P &lt; 0.001) on daily grazing time. Animals on high SR (431 min per animal) spent greater time grazing than those on low SR (371 min per animal). There was no difference in time spent grazing on each component of the adjacent monocultures of grass and legume within the SS (P = 0.23; 197 [the monoculture legume component of a SS] vs. 182 min per animal [monoculture grass component of a SS]). Less grazing time by animal on SS than MG and MIX may have implications for performance of animals grazing such a system because of expected lesser energy expenditure for grazing.

Effects of tropical high tannin non legume and low tannin legume browse mixtures on fermentation parameters and methanogenesis using gas production technique.

In vitro experiments were conducted to evaluate the suitability of several mixtures of high tanniniferous non legumes with low tanniniferous legumes on in vitro gas production (IVGP), dry matter degradation, Ammonia-N, methane production and microbial population. Eight treatments were examined in a randomized complete block design using four non-legumes and two legumes (Carallia integerrima×Leucaena leucocephala (LL) (Trt 1), C. integerrima×Gliricidia sepium (GS) (Trt 2), Aporosa lindeliyana×LL (Trt 3), A. lindeliyana×GS (Trt 4), Ceiba perntandra×LL (Trt 5), C. perntandra×GS (Trt 6), Artocarpus heterophyllus×LL (Trt 7), A. heterophyllus×GS (Trt 8). The condensed tannin (CT) content of non legumes ranged from 6.2% (Carallia integerrima) to 4.9% (Ceiba perntandra) while the CT of legumes were 1.58% (Leucaena leucocephala) and 0.78% (Gliricidia sepium). Forage mixtures contained more than 14% of crude protein (CP) while the CT content ranged from 2.8% to 4.0% respectively. Differences (p<0.05) were observed in in vitro gas production (IGVP) within treatments over a 48 h period dominated by C. perntandra×G. sepium (Trt 6). The net gas production (p<0.05) was also high with Trt6 followed by A. heterophyllus×L. leucocephala (Trt 7) and A. heterophyllus×G. sepium (Trt 8). Highest (p>0.05) NH3-N (ml/200 mg DM) production was observed with the A. heterophyllus×G. sepium (Trt 8) mixture which may be attributed with it’s highest CP content. The correlation between IVGP and CT was 0.675 while IVGP and CP was 0.610. In vitro dry matter degradation (IVDMD) was highest in Trt 8 as well. Methane production ranged from 2.57 to 4.79 (ml/200 mg DM) to be synonimous with IVGP. A higher bacteria population (p<0.05) was found in C. perntandra×G. sepium (Trt 6) followed by Artocarpus heterophyllus+G. sepium (Trt 8) and the same trend was observed with the protozoa population as well. The results show that supplementing high tannin non leguminous forages by incremental substitution of legume forage increased gas production parameters, NH3-N, IVDMD and microbial population in the fermentation liquid. Methane production was not significantly affected by the presence of CT or different levels of CP in forage mixtures. Among non legumes, Ceiba perntandra and Artocarpus heterophyllus performed better in mixture with L. leucocephala and G. sepium.

Comparison of feeding value of a treated sea plant, Posidonia australis, with lucerne, pasture and wheat

An experiment was carried out to compare the effect of feeding posidonia australis as a non-conventional feedstuff with cereal straw for sheep maintenance; and to compare seagrass/chicken litter with lucerne hay and pasture for sheep production on a scale such as would be applicable to lot-feeding of sheep in the area of suthern Australia in case of short term feed scarcity. To approach this target a Randomized Completely Block Design with six treatments was applied on sixty adult merino. The six experimental diets were: (A) 75% treated seagrass+25% lucerne; (B) 75% treated wheat straw+25% lucerne; (C) 75% treated wheat straw+25% chicken litter (seagrass bed+chicken manure from a 7-week broiler raising period); (D) 50% treated wheat straw+50% treated seagrass; (E) 100% treated straw; (F) Green pasture, mixture of legume and graminea. To treat seagrass and straw a solution containing 8% fertilizer grade urea, 15% sugarcane molasses and 1% calcium-diphosphate was mixed with either seagrass or straw (1 Kg/Kg DM). The mixture was stored under anaerobic conditions for 3 weeks. The total experimental period of 109 days was used to measure the effect of experimental rations on the voluntary intake, body weight gain, fat score, feed efficiency and wool growth rate of sheep. There were different DMI of diets A, B and C during the experiment but these differences were not significant. Similar results were obtained for diets D and E as well. Among sheep of groups A, B and C total body gain of the sheep in group A was significantly less than that of the other two groups. The body weight gain of sheep grazed on pasture was significantly less than that of the sheep groups B and C, more than for the sheep in groups D and E (P<0.05) and equal that of the to sheep group A. In general there were few statistical differences, except that sheep on diet A showed consistently lowest values for greasy and clean fleece weight, staple growth rate, length: diameter ratio and staple strength. There was not a significant difference in clean fleece growth rate between sheep grazed on pasture and sheep in diet groups B, C, D and E, but this value was higher than for sheep in group A. It can be suggested that seagrass litter can be used proportionally in a mixed diet to provide enough nutrients and energy for sheep production in time of drought or feed scarcity. Meanwhile the cheaper diets D (seagrass containing) or E (straw only) could be used with equal efficiency in a lot-feeding system.

Production and Economics of Grazing Steers on Rye–Annual Ryegrass with Legumes or Fertilized with Nitrogen

ABSTRACTCool‐season legumes have potential to replace N fertilizer in annual cool‐season grass pastures, thus improving returns to producers. The objective of this 3‐yr study was to compare the performance and economics of stocker cattle (Bos spp.) grazing rye (Secale cereale L.)–annual ryegrass (Lolium multiflorum Lam.) under two N systems. Paddocks were planted in early September 2008 through 2010 and contained rye–annual ryegrass with 112 kg N ha−1 (fertilized so that a total of soil residual N plus fertilizer N would equal 112 kg N ha−1) (RR‐N) or contained a rye–annual ryegrass with annual legume mixture (arrowleaf clover [Trifolium vesiculosum Savi], field pea [Pisum sativum L.], and hairy vetch [Vicia villosa Roth]) (RR‐Leg). Steers (307 ± 55 kg initial body weight) were weighed every 28 d and stocking rates were adjusted based on forage mass with put‐and‐take steers. Forage mass, forage allowance, and stocker average daily gain (ADG) and total gain (TG) were measured every 28 d. Results show similar performance between RR‐N and RR‐Leg systems in grazing days (average 367 d ha−1), ADG (average 1.065 kg per head d−1), and TG (average 390 kg ha−1). While the 3‐yr average total cost associated with the RR‐N system (US$569.88 ha−1) was greater than the RR‐Leg system ($550.57 ha−1), there were no differences in gross revenue (average $815.91 ha−1) or expected net returns (average $255.68 ha−1) between systems. Annual legumes could be a viable replacement for commercial N fertilizer in rye–annual ryegrass pastures although adoption may be limited due to ease of N fertilizer application.

Production and Economics of Steers Grazing Tall Fescue with Annual Legumes or Fertilized with Nitrogen

ABSTRACTUse of cool‐season forage legumes may decrease production costs and improve returns to beef cattle (Bos spp.) producers. The objective of this 3‐yr field study was to compare the performance and economics of stocker cattle grazing tall fescue {Festuca arundinacea Schreb. [syn. Schedonorus arundinaceus (Schreb.) Dumort] ‘Texoma MaxQ II’} under two N systems. Paddocks (0.81 ha) were either a tall fescue with 112 kg N ha−1 (fertilized so that a total of soil residual N plus fertilizer would equal 112 kg N ha−1) (TF‐N) or contained a tall fescue with annual legume mixture (arrowleaf clover [Trifolium vesiculosum Savi], hairy vetch [Vicia villosa Roth], and field pea [Pisum sativum L.] (TF‐Leg). Steers (Bos taurus; 282 ± 67 kg initial body weight) were weighed every 28 d during each grazing season, and stocking rates were adjusted based on forage mass with put‐and‐take steers. In each 28‐d grazing period, forage mass, forage allowance, and stocker average daily gain (ADG) and total gain (TG) were measured. Results show a greater number of grazing days (429 and 334 d ha−1, respectively; p = 0.03) were associated with the TF‐N system than the TF‐Leg system while animal performance (ADG of 0.70 kg per head d−1; p = 0.61) and TG (296 and 237 kg ha−1; p = 0.10) were similar. The 3‐yr average total cost with establishment and gross revenue were similar between the TF‐N (US$460.67 and $691.16 ha−1, respectively) and TF‐Leg systems ($466.79 and $553.33 ha−1, respectively). However, the TF‐N system showed a tendency toward greater expected net return than the TF‐Leg system ($224.35 and $92.67 ha−1, respectively; p = 0.08).

Set-aside fields in agri-environment schemes can replace the market-driven abolishment of fallows

Economic pressures from increased commodity prices and the growing demand for land for biomass plantations led to the abolition of compulsory set-aside fields in the European Union in 2008, affecting ca. 10% of total agricultural area. This area is now managed more intensively, and this is expected to adversely affect farmland biodiversity. Unfortunately, no mitigation of set-aside loss was introduced. Here we examined, whether or not set-aside fields managed in voluntary agri-environment schemes have the potential to improve farmland bird populations, as indicators of farmland biodiversity. We chose one, two and three year-old set-aside fields sown by a grass–legume mixture when established and selected winter cereal fields and semi-natural grasslands in Hungary as control sites. Relative abundance of birds was assessed; species were assigned to feeding guilds and classified according to their European conservation status. Species richness of herbaceous plants, cover of bare ground and vegetation height were used as covariates. Set-aside fields had higher species richness and abundance of birds compared to the adjacent winter cereal fields, similar to semi-natural grasslands. We found a positive correlation between set-aside age and farmland bird species richness and abundance. This can be explained mainly by the altered vegetation, especially the shorter vegetation height from the second year in the set-aside fields. We found no difference in the distribution pattern of species richness and abundance between feeding guilds according to set-aside age and habitat types. The wide scale application of voluntary set-aside management in agri-environment programs therefore has a high potential to mitigate the negative effects from the loss of compulsory set-aside schemes, and thus need the allocation of considerable resources in the forthcoming reformed CAP.

Yield and yield stability in mixtures of productive grassland species: Does species number or functional group composition matter?

AbstractIn productive agricultural grasslands the relative importance of species identity, species richness and functional group composition for production and yield stability is not clear. We, therefore, tested diversity effects in mixtures of five productive species common in temperate agricultural grasslands in a greenhouse study: Trifolium repens (legume), Lolium perenne, Dactylis glomerata (grasses) and Plantago lanceolata, Taraxacum officinale agg. (forbs). Diversity levels were (i) monoculture; (ii) all possible three‐species mixtures; and (iii) five‐species mixture. Biomass production increased with greater species richness, an effect that was interpreted as a functional response to a higher proportion of legumes in the mixtures. Species identity and functional composition influenced yield and yield stability in different ways. Larger contents of the legume in mixtures increased yield but decreased yield stability while grasses showed the opposite effect in mixtures. The biomass production of forbs was mostly small in mixtures and yield stability decreased with increasing presence of forbs. In productive agricultural grassland, functional group composition, especially the presence of legumes and grasses, seems to be more important for productivity and yield stability than diversity.

Pea–wheat intercrops in low-input conditions combine high economic performances and low environmental impacts

Intensive agriculture ensures high yields but can cause serious environmental damages. The optimal use of soil and atmospheric sources of nitrogen in cereal–legume mixtures may allow farmers to maintain high production levels and good quality with low external N inputs, and could potentially decrease environmental impacts, particularly through a more efficient energy use. These potential advantages are presented in an overall assessment of cereal–legume systems, accounting for the agronomic, environmental, energetic, and economic performances. Based on a low-input experimental field network including 16 site-years, we found that yields of pea–wheat intercrops (about 4.5Mgha−1 whatever the amount of applied fertiliser) were higher than sole pea and close to conventionally managed wheat yields (5.4Mgha−1 on average), the intercrop requiring less than half of the nitrogen fertiliser per ton of grain compared to the sole wheat. The land equivalent ratio and a statistical analysis based on the Price's equation showed that the crop mixture was more efficient than sole crops particularly under unfertilised situations. The estimated amount of energy consumed per ton of harvested grains was two to three times higher with conventionally managed wheat than with pea–wheat mixtures (fertilised or not). The intercrops allowed (i) maintaining wheat grain protein concentration and gross margin compared to wheat sole crop and (ii) increased the contribution of N2 fixation to total N accumulation of pea crop in the mixture compared to pea sole crop. They also led to a reduction of (i) pesticide use compared to sole crops and (ii) soil mineral nitrogen after harvest compared to pea sole crop. Our results demonstrate that pea–wheat intercropping is a promising way to produce cereal grains in an efficient, economically sustainable and environmentally friendly way.

INVESTIGATING COMPONENT SPECIES PROPORTIONS IN A CEREAL-LEGUME COVER CROP MIXTURE UNDER ORGANIC MANAGEMENT

ISHS XXVIII International Horticultural Congress on Science and Horticulture for People (IHC2010): International Symposium on Organic Horticulture: Productivity and Sustainability INVESTIGATING COMPONENT SPECIES PROPORTIONS IN A CEREAL-LEGUME COVER CROP MIXTURE UNDER ORGANIC MANAGEMENT

Forage legume species determine the nutritional quality of binary mixtures with perennial ryegrass in the first production year

There is increasing interest in forage legumes as ruminant feeds in Europe as alternatives to using mineral N fertilizer on temporary grassland. Successful management of grass–legume mixtures depends on the suitability of the forage legume species to the cutting frequency, and its nutritional quality for animals. An experiment was completed in 2004 and 2005 on two sites at the University of Kiel (Germany) to examine the response of legume-perennial ryegrass (Lolium perenne L.) mixtures to cutting frequency in terms of dry matter (DM) yield, N2 fixation, net energy for lactation (NEl), plant cell wall content, and crude protein (CP) content and CP fractions in the first production year. Different legumes in binary mixtures with perennial ryegrass (L. perenne L.), red clover (Trifolium pratense L.), white clover (Trifolium repens L.), hay-type and grazing-type alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus corniculatus L.), Caucasian clover (Trifolium ambiguum M. Bieb.) and two monocultures of perennial ryegrass (with and without cattle slurry supplying 20gN/m2) were examined under two cutting frequencies. All legume–grass mixtures outperformed perennial ryegrass with and without slurry in terms of DM yield, irrespective of cutting frequency. Production from both birdsfoot trefoil and Caucasian clover in grass–legume mixtures were very low, similar to unfertilized pure stands of grass, and the low production was consistent with slow and deficient establishment of birdsfoot trefoil and Caucasian clover, as observed by others. Nutritional quality of Caucasian clover was comparable to white clover. The companion grass benefited from the N transferred by forage legumes and their growth habit. This was especially evident for white clover, resulting in the highest companion grass yield and, in consequence, high mixture DM yield in both the 3 and 5 cut systems. Differences in agronomic performance of the legume–grass mixtures, and the grass monocultures, were related to the legume species in the mixture rather than cutting system. Forage legume species determined the nutritional quality and yield of binary mixtures with perennial ryegrass in the first production year.

Yield and yield structure of spring barley (Hodeum vulgare L.) grown in monoculture after different stubble crops

A field experiment was conducted in the period 2006- 2008 in the Uhrusk Experimental Farm belonging to the University of Life Sciences in Lublin. The experimental factor was the type of stubble crop ploughed in each year after harvest of spring barley: white mustard, lacy phacelia, winter rape, and a mixture of narrow-leaf lupin with field pea. In the experiment, successive spring barley crops were grown one after the other (in continuous monoculture). The aim of the experiment was to evaluate the effect of stubble crops used on the size and structure of barley yield. The three-year study showed an increasing trend in grain yield of spring barley grown after the mixture of legumes, lacy phacelia, and white mustard compared to its size in the treatment with no cover crop. Straw yield was significantly higher when barley was grown after the mixture of narrowleaf lupin with field pea than in the other treatments of the experiment. The type of ploughed-in stubble crop did not modify significantly plant height, ear length, and grain weight per ear. Growing the mixture of leguminous plants as a cover crop resulted in a significant increase in the density of ears per unit area in barley by an average of 14.7% relative to the treatment with winter rape. The experiment also showed the beneficial effect of the winter rape cover crop on 1000-grain weight of spring barley compared to that obtained in the treatments with white mustard and the mixture of legumes. All the cover crops caused an increase in the number of grains per ear of barley relative to that found in the control treatment. However, this increase was statistically proven only for the barley crops grown after lacy phacelia and the mixture of legumes.