Journal articles on the topic 'Medic-cereal'
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1
Peck, David M., Simon Michelmore, and Tim Sutton. "Genetic analysis of boron tolerance in burr medic (Medicago polymorpha L.)." Crop and Pasture Science 72, no. 9 (2021): 634. http://dx.doi.org/10.1071/cp20263.
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Soils with toxic levels of boron (B) are widespread in the cereal-livestock zone of southern Australia. The annual pasture legume burr medic (Medicago polymorpha L.) is widely grown in rotation with grain crops in this zone, but current cultivars are susceptible to high levels of B. We tested the boron tolerance of several putative B tolerant burr medic accessions and developed four F2 populations by crossing two tolerant accessions with two susceptible cultivars. We tested a B tolerance SSR marker developed for barrel medic (M. truncatula Gaernt) on tolerant burr medic accessions but found a new marker was required. We identified several B tolerant burr medic accessions. In our four F2 populations tolerance was inherited in a 3:1 (tolerant:susceptible) ratio and we identified a molecular marker that accounts for 0.84 of the variation. The B tolerant accessions, along with the B tolerance marker, will allow for the efficient introgression of B tolerance into widely adapted genetic backgrounds and will allow breeders to efficiently develop cultivar(s) that are tolerant of a widespread subsoil constraint.
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B. A. and L. Chatterton. "A hypothetical answer to the decline of the Granary of Rome?" Libyan Studies 16 (1985): 95–99. http://dx.doi.org/10.1017/s0263718900007329.
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AbstractIn an earlier paper, we argued that medic pasture was probably an important component of the ancient farming regime in Libya. The success of modern experiments which have reintroduced medicago pasture was also described.In this paper, the analysis is taken further and the results of different types of crop rotation are compared. The Waite experiment in Australia has shown that the most intensive systems of cereal cultivation are not necessarily the most productive, when soil exhaustion and long term decline in yields are taken into account. In fact, the highest profits and best returns of both cereals and livestock are obtained from low intensity systems.It is possible that increased emphasis on cereal production in the Roman period may have led to a diminuation of the medic pasture, to the exhaustion of the soils and falling yields. By its own initial success, Romano-Libyan agriculture may have contributed to its own decline.
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Latta, RA, and PE Quigley. "A comparison of the persistence of Medicago truncatula cv. Paraggio with other annual medics in the Victorian Mallee." Australian Journal of Experimental Agriculture 33, no. 4 (1993): 443. http://dx.doi.org/10.1071/ea9930443.
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The annual medic Medicago truncatula cv. Paraggio has been widely sown in pastures throughout the Victorian Mallee region; however, its ability to persist in cereal pasture rotations is not known. Seed permeability and production, and plant regeneration of Paraggio, were studied in the field over 4 years, and the changes in its seed reserve were examined under 3 different cereal-pasture rotations. When compared with medic cvv. Parabinga, Harbinger, and Jemalong, Paraggio had up to twice the level of permeable seed over the summer-autumn period in 2 years (7-36% v. 2.5-19%). Paraggio produced 336-928 kg/ha of seed over 3 years, and after seed production was halted, it regenerated at densities of 150-1438 plants/m2 over the next 4 years. These results were generally the same as, or better than, the other cultivars. When seed set occurred in 1 and 2 years in the pasture phase of a 2- and 3-year rotation, respectively, Paraggio seed reserves were maintained at >4000 seeds/m2. This study demonstrated that Paraggio resulted in superior plant densities when grown in a number of typical rotations. It persisted satisfactorily and is expected to improve agricultural productivity in shor-tterm cereal-pasture rotations.
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Lloyd, D. L., G. B. Taylor, B. Johnson, and K. C. Teasdale. "Patterns of seed softening and seedling emergence of nineteen annual medics during three years after a single seed crop in southern Queensland." Australian Journal of Experimental Agriculture 37, no. 7 (1997): 767. http://dx.doi.org/10.1071/ea97060.
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Summary. To produce seed to determine the rates of seed softening of annual medics in the subtropics, 8 lines of barrel medic (Medicago truncatula), 3 lines of burr medic (M. polymorpha), 4 lines of snail medic (M. scutellata), and 1 line of each of button medic (M. orbicularis), strand medic (M. littoralis) and gama medic (M. rugosa) were grown at Warra in southern inland Queensland, in 1993. Seed of a fourth line of burr medic, a naturalised line, was harvested from Hermitage Research Station at that time. Pods were placed on the soil surface and buried at a depth of 7 cm, both in flywire envelopes and as free pods. Residual hard seed numbers were determined each year for 3 years from the envelopes, and seedlings were counted and removed from the free pods after each germination event. Patterns of softening of seeds from the same seed populations were also determined after placing them in a laboratory oven with a diurnal temperature fluctuation of 60/15° C for periods of 16, 40 and 64 weeks followed, after each time period, by 4 diurnal cycles of 35/10°C. More than 90% of the original seeds were hard. Seed softening at the soil surface ranged from 26% after 3 years in button medic to almost complete softening in the gama medic after only 2 years. Burial had little effect on the rate of softening of the button medic but about halved the rate of softening of the other lines. The barrel medics were vulnerable to losses of large numbers of seedlings which softened and germinated in January–February and the snail medics from seedlings emerging in August–December. The proportion of soft seeds recovered as seedlings in the buried compared with the surface pods was higher in the larger-seeded medics, snail and gama, and lower in the other, smaller-seeded medics. Laboratory techniques effectively ranked the medic lines for their rate of seed softening in the field and provided some insight into their seasonal patterns of seed softening. A wide range of seed softening patterns is available for fitting the requirements of various farming systems. The most appropriate pattern of softening will depend on the variability of medic seed production between years and the need for self regeneration of the medic after a cereal crop.
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RYAN, J., M. SINGH, M. PALA, R. MAKHBOUL, S. MASRI, H. C. HARRIS, and R. SOMMER. "Crop sequences, nitrogen fertilizer and grazing intensity in relation to wheat yields in rainfed systems." Journal of Agricultural Science 148, no. 2 (January 21, 2010): 205–16. http://dx.doi.org/10.1017/s0021859609990566.
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SUMMARYThe Mediterranean region is experiencing unrelenting land-use pressure, largely driven by population growth. Long-term cropping system trials can guide crop and soil management options that are biophysically and economically sustainable. Thus, an extensive cereal-based rotation trial (1983–98) was established in northern Syria, to assess various two-course rotations with durum wheat (Triticum turgidum Desf.). The alternative rotations were: continuous wheat, fallow, chickpea (Cicer arietinum), lentil (Lens culinaris), medic (Medicago spp.), vetch (Vicia sativa) and watermelon (Citrullus vulgaris) as a summer crop. Ancillary treatments were: nitrogen (N) fertilizer application to the cereal phase (0, 30, 60 and 90 kg N/ha) and variable stubble grazing management (zero or stubble retention, moderate and heavy grazing). Both phases of the rotation trial occurred each year. The soil is a fine clay, thermic Calcixerollic Xerochrept. Seasonal rainfall was the dominant factor in influencing overall yields. Rotations significantly influenced yields, being highest for fallow (2·43 t/ha), followed by watermelon (similar to fallow), vetch, lentil, medic and chickpea, and least for continuous wheat (1·08 t/ha). Overall, yields increased consistently with added N, but responses varied with the rotation. The various stubble grazing regimes had little or no effect on either grain or straw yields. While the trial confirmed the value of fallow and the drawbacks of continuous cereal cropping, it also showed that replacing either practice with chickpea or lentil, or vetch for animal feed, was potentially a viable option. Given favourable economics, legume-based rotations for food and forage could contribute to sustainable cropping throughout the Mediterranean region.
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Weston, E. J., R. C. Dalal, W. M. Strong, K. J. Lehane, J. E. Cooper, A. J. King, and C. J. Holmes. "Sustaining productivity of a Vertisol at Warra, Queensland, with fertilisers, no-tillage or legumes. 6. Production and nitrogen benefits from annual medic in rotation with wheat." Australian Journal of Experimental Agriculture 42, no. 7 (2002): 961. http://dx.doi.org/10.1071/ea01083.
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Continuous cereal production in the summer-dominant rainfall region of north-eastern Australia has depleted native soil nitrogen fertility to a level where corrective strategies are required to sustain wheat grain yields and high protein levels for domestic and export markets. Annual medic pastures, along with other strategies, were evaluated from 1986 to 1998 on a Vertisol at Warra, southern Queensland, for their benefit to subsequent grain yield and protein content of wheat.Annual medic production and nitrogen yields were closely correlated with the growing season rainfall (March–September). Each 100 mm of growing season rainfall resulted in 1.39 t/ha of dry matter and 40 kg/ha of N yield. There were significant increases in soil mineralisable nitrogen following annual medic leys compared with continuous wheat in most years, but increases in total soil nitrogen were only observed in 1990, 1991 and 1992. However, pre-plant nitrate-nitrogen following an annual medic ley was always higher than that of continuous wheat without nitrogen fertiliser. This resulted in significant increases in wheat yield (6 of 9 seasons) and grain protein (in all seasons) compared with continuous wheat. The overall responses in yield and protein were similar to those of 50� kg/ha of fertiliser nitrogen applied to continuous wheat crops. A nitrogen harvest budget for the annual medic–wheat rotation over 11 years showed that it contributed 131 kg N/ha more than continuous wheat. Thus, using the seasonal conditions experienced from 1987 to 1998 as a reasonable representation of the rainfall range in the region, sustainable productivity can be maintained where annual medics are grown in short rotations with wheat.
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Peck, D. M., and J. H. Howie. "Development of an early season barrel medic (Medicago truncatula Gaertn.) with tolerance to sulfonylurea herbicide residues." Crop and Pasture Science 63, no. 9 (2012): 866. http://dx.doi.org/10.1071/cp12130.
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Sulfonylurea (SU) herbicides are extensively applied to crops in the cereal-livestock zones of southern Australia. In low rainfall areas with alkaline soils, SU residues can persist over summer and can severely affect sown or regenerating medic pastures. A cohort of early season barrel medics (Medicago truncatula) bred and selected for tolerance to SU herbicide residues were evaluated at multiple field sites over 3 years (year of establishment and subsequent regeneration). Two lines (Z2438 and Z2415) were identified which had dry matter production and seed yield in the establishment year equivalent to their recurrent parent, Caliph, an early maturing, aphid-tolerant, barrel medic cultivar. They also had lower levels of hardseededness than Caliph, enabling them to regenerate in greater numbers in the following year and thus produce more dry matter. The two lines demonstrated good tolerance to simulated SU herbicide residues, producing up to 10 times the dry matter of the SU-intolerant parent Caliph. We anticipate that one or both of the two lines will be commercialised soon, enabling farmers in low rainfall areas with neutral-to-alkaline soils to successfully grow barrel medic pastures in the presence of SU herbicide soil residues resulting from applications to prior crops.
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Dehaghi, Majid Amini, and Seyed Ali Mohammad Modarres Sanavy. "Effect of root-zone temperatures on morphology, growth and development, yield, and yield components of annual medics." Australian Journal of Agricultural Research 54, no. 9 (2003): 917. http://dx.doi.org/10.1071/ar02067.
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Annual medic pastures are an effective component of ley-farming systems (cereal–legume rotations) in Australian areas with a Mediterranean climate, but they have been unsuccessful in areas near the Mediterranean Sea. In some zones with a Mediterranean climate, like Iran and Syria, root-zone temperature is considered the major growth-limiting factor for annual medic early in the growing season. In order to study the effect of low root-zone temperature (RZT) on growth and development, yield, and yield components of some annual Medicago species, an experiment was conducted in a controlled-environment chamber. In this experiment, 3 species of annual medics, namely Medicago polymorpha, M. radiata, and M. rigidula, thought to be adapted to cold and temperate conditions, were used. Four root-zone temperatures (5, 10, 15, and 20�C) were considered. The experimental layout was a completely randomised block design with 4 replications. There were differences among the annual medics for dry matter and yield components. Two species, M. polymorpha and M. rigidula, had more leaf, stem, and root dry matter, plant height, leaf and stem to root ratio, leaf to stem ratio, and leaf area and yield than M. radiata. Therefore, M. polymorpha and M. rigidula may be better suited for ley-farming systems in cold and temperate zones. The results also showed that the 5�C RZT effectively decreased the yield and yield components of the annual medics. In conclusion, application of ley-farming is not likely to be successful when RZT is below 5�C, especially during vegetative development. Therefore, in the zones where soil temperature is greater than 10�C, annual medics have normal growth and produce average yields. Ley-farming (cereal–legume rotation) could be replaced with fallow–cereal rotation.
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Latta, R. A., and E. D. Carter. "Increasing production of an annual medic - wheat rotation by grazing and grass removal with herbicides in the Victorian Mallee." Australian Journal of Experimental Agriculture 38, no. 3 (1998): 211. http://dx.doi.org/10.1071/ea95057.
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Summary. The productivity of an annual medic-based pasture–pasture–wheat rotation in response to chemical grass control and stocking rate treatments was evaluated over 3 years. Fluazifop applied in 1991 reduced the annual grass component during the pasture years (to <2% in 1991 and <5% in 1992) and grass densities in the 1993 wheat phase. This improved winter herbage production in 1992 (>50%) and the 1993 wheat yield (>40%). Glyphosate applied during the winter of 1991 reduced the grass component and the winter and total herbage production in that year, and grass populations in 1992. Glyphosate applied during the spring of 1991 reduced the medic seed yields and the grass and medic densities in 1992. There were no pasture or cereal production benefits measured from the 1991 glyphosate applications. All the above comparisons were made with no herbicide in 1991 followed by glyphosate applied during the winter of 1992, a common district practice. Stocking at twice the district average, over all herbicide treatments, reduced the 1991 winter herbage production but maintained or improved the 1992 winter and total herbage production, compared with the district average stocking rate. The high stocking rate resulted in lower grass densities in the 1993 wheat crop and increased the wheat grain yield by 0.5 t/ha.
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Blair, Nelly, R. D. Faulkner, A. R. Till, and P. Sanchez. "Decomposition of 13C and 15N labelled plant residue materials in two different soil types and its impact on soil carbon, nitrogen, aggregate stability, and aggregate formation." Soil Research 43, no. 7 (2005): 873. http://dx.doi.org/10.1071/sr04137.
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Increasing soil organic matter (SOM) is a major factor in overcoming soil degradation. An incubation experiment using 2 soil types (Red Clay and Black Earth) and 2 different rotations, a clover (Trifolium subterraneum)/cereal rotation and a long fallow/cereal rotation, from a long-term crop rotation trial located at Tamworth, NSW, Australia was conducted to investigate the decomposition of 3 different plant materials, medic (Medicago truncatula) (C : N = 13), rice straw (Oryza sativa) (C : N = 25) and flemingia leaf (Flemingia macrophylla) (C : N = 13), labelled with 13C and 15N. A control treatment with no added residue was also included. The impact of the residue decomposition on total organic carbon, labile carbon, total nitrogen, aggregate stability and the formation of large macro-aggregates from smaller macro-aggregates were studied. Total C (CT), stable carbon isotope composition (δ13C), total N (NT), and %15N excess were measured by catalytic combustion and an isotope ratio mass spectrophotometer, while labile C (CL) was determined by oxidation with KMnO4. Aggregate stability [mean weight diameter (MWD)] was determined by immersion wet sieving. Correlations of C fractions with MWD were also investigated. The location of the newly added plant residue materials within soil aggregates was studied using a soil aggregate eroding machine. Loss of C from the added plant residues was highest for the medic and lowest for the flemingia, while the rice straw initially lost C at a slower rate but by 200 days was equal to the medic. The medic treatment was the only residue to lose N by gaseous loss during the experiment and it was all lost during the first 10 days. In both soils, the addition of residues increased CT and CL compared with the control treatment, with flemingia showing the greatest increase. Factors other than their C : N ratio were clearly determining C turnover. Addition of medic residues resulted in a rapid increase in MWD in both soils in the first 10 days compared with that at the commencement of the experiment. However, this was not maintained for the 200 days by which time MWD had decreased, but it was still greater than the starting point. By contrast, the addition of flemingia leaf exhibited a slower but more sustained increase to have the highest MWD at 200 days, equal to that of the medic treatment at 10 days. There was a positive correlation of CL with MWD at 200 days for both soils. Results from the soil aggregate eroding machine showed that a higher percentage of CT was derived from added plant residues in the outer one-third of the soil aggregates than in the inner two-thirds, with the greatest difference being for the flemingia treatment. There was no difference between different residue materials in the amount of CT derived from the added residues in the inner parts of soil aggregates. These results showed that soil macro-aggregates were forming around a central old aggregate by binding of smaller aggregates to it, with products formed as a result of the breakdown of plant residues binding them together. From the results obtained, and those of other researchers, a concept of macro-aggregate formation under different agricultural systems is proposed.
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Harvey, P. R., P. J. Butterworth, B. G. Hawke, and C. E. Pankhurst. "Genetic and pathogenic variation among cereal, medic and sub-clover isolates of Pythium irregulare." Mycological Research 105, no. 1 (January 2001): 85–93. http://dx.doi.org/10.1017/s0953756200002902.
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Howie, J. H. "Boron tolerance in annual medics (Medicago spp.)." Crop and Pasture Science 63, no. 9 (2012): 886. http://dx.doi.org/10.1071/cp12143.
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Boron (B) is present at toxic levels in the subsoils of much of the semiarid south-eastern Australian cereal-livestock zone. Boron toxicity is typically associated with alkaline soils, where annual medics (Medicago spp.) are generally the best-adapted pasture legume. New medic cultivars have been developed for which there is no published B tolerance information. Five species of annual medic represented by 13 cultivars were grown in soil amended with B and evaluated for B tolerance. A rating system based on expression of symptoms was modified from earlier research. There was a wide range of response to B, both between and within species. Cultivars varied widely in their expression of symptoms; from showing no or few leaf symptoms (tolerant) to significant leaf necrosis (very sensitive). An integrated summary of both published and previously, unpubl. data for these and other medics is presented to provide a comprehensive and up-to-date comparison between different species and most commercial cultivars. This information will be useful for plant breeders, agronomists and farmers who manage soils with high B levels.
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Christiansen, Scott, John Ryan, Murari Singh, Serkan Ates, Faik Bahhady, Khalil Mohamed, Omran Youssef, and Stephen Loss. "Potential legume alternatives to fallow and wheat monoculture for Mediterranean environments." Crop and Pasture Science 66, no. 2 (2015): 113. http://dx.doi.org/10.1071/cp14063.
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Growing populations and intensification of land-use in West Asia and North Africa (WANA) are prompting a need for viable alternatives to fallow and cereal mono-cropping systems common in dry areas of this region. The sustainability and economic viability of such rotations can only be assessed accurately by using long-term trials. A two-course rotation experiment was established in 1986 in north-eastern Syria, comparing yields and profitability of wheat (Triticum aestivum L.) when grown after wheat, fallow, a grazed mixture of medic species (Medicago spp.) and common vetch (Vicia sativa L.) cut for hay, over 10 growing seasons. Lentils (Lens culinaris Medik.) were introduced into the experiment in 1990. On average over the course of the experiment, the highest wheat grain yields were obtained following fallow (2.57 t ha–1), the lowest in continuous wheat (1.14 t ha–1), and intermediate following medic and vetch (1.90–2.01 t ha–1). Compared with wheat grown after fallow, wheat grain yields declined following vetch, medic and lentils in only three of the 10 seasons, which were drier than average. Yields of wheat after lentils were generally lower (2.22 t ha–1) than after vetch (mean 2.56 t ha–1) and after medic (2.40 t ha–1). Inclusion of grain legumes in the rotations boosted profits considerably because of their high grain prices and valuable straw. Replacing fallow with vetch for hay production increased the average gross margin by US$126 ha–1 year–1, and growing vetch for hay in rotation with wheat produced greater profit than continuous wheat, by $254 ha–1 year–1. The wheat–vetch-for-grain and wheat–lentil rotations were especially profitable, at least twice as profitable as wheat–fallow and three times continuous wheat. This experiment adds to the growing body of field data in Syria and in Australia showing that forage and grain legumes are excellent alternatives to wheat–fallow rotation and continuous wheat production in areas that experience a Mediterranean-type climate, and help support more efficient and sustainable cropping systems.
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WRIGHT, A. T. "YIELD EFFECT OF PULSES ON SUBSEQUENT CEREAL CROPS IN THE NORTHERN PRAIRIES." Canadian Journal of Plant Science 70, no. 4 (October 1, 1990): 1023–32. http://dx.doi.org/10.4141/cjps90-125.
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A study comparing the crop sequences pulse-barley-wheat and barley-barley-wheat, was conducted from 1982 to 1987 on Black and Gray-wooded soils in northeastern Saskatchewan. Faba bean (Vicia faba L.), field pea (Pisum sativum L.), and lentil (Lens culinaris Medic.) had similar effects, increasing subsequent cereal yield, on average, by 21% in the first and 12% in the second year. Incorporation of pulse residue was not necessary in order to attain high yields. The yield response of barley (Hordeum vulgare L.) to N fertilizer was slightly greater on barley than on pulse residue, but N fertilizer alone was unable to bring the yield on barley residue up to the yield on pulse residue. However, there were great differences in the effect of year, soil type, preceding crop, residue incorporation, and fertilizer response, and there were many significant interactions of these treatments. These treatment effects could not be consistently accounted for by differences in N cycling, soil moisture, or disease.Key words: Barley, faba bean, field pea, lentil, wheat, crop sequence
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Franklin-McEvoy, J., W. D. Bellotti, and D. K. Revell. "Supplementary feeding with grain improves the performance of sheep grazing saltbush (Atriplex nummularia) in autumn." Australian Journal of Experimental Agriculture 47, no. 8 (2007): 912. http://dx.doi.org/10.1071/ea06149.
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Merino wethers aged 1.5 years grazed a saltland pasture comprising old man saltbush (Atriplex nummularia) with an inter-row of senesced grasses and medic for 6 weeks in autumn, in a cereal–livestock zone with a Mediterranean-type environment in South Australia. The experimental treatments were a control (old man saltbush, SB), supplementation with 250 g/sheep.day barley straw (SB + S), supplementation with 250 g/sheep.day barley grain (SB + G) and supplementation with 250 g/sheep.day barley straw + 250 g/sheep.day barley grain (SB + S + G). The sheep in SB + G finished the experimental period significantly heavier (53.6 kg, P < 0.001) than SB (51.0 kg), SB + S (50.5 kg) or SB + S + G (51.1 kg) animals. Feeding grain also increased length of wool grown daily by 16% and would have increased the value of the sheep by being able to sell them ‘out of season’ when prices are higher. Sheep supplemented with grain alone had a higher liveweight than those provided with grain and straw, a result that cannot be explained but may be associated with altered grazing behaviour. It appears that, while old man saltbush provides sheep with an acceptable intake of protein and minerals, the addition of a cereal grain supplement improves energy balance and optimises rumen protein capture to improve liveweight and wool growth performance.
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Brockwell, J. "Sinorhizobium meliloti in Australian soils: population studies of the root-nodule bacteria for species of Medicago in soils of the Eyre Peninsula, South Australia." Australian Journal of Experimental Agriculture 41, no. 6 (2001): 753. http://dx.doi.org/10.1071/ea00194.
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Populations of Sinorhizobium meliloti(formerly Rhizobium meliloti — the root-nodule bacteria for Medicago) from soils at 32 sites on the Eyre Peninsula, South Australia, were enumerated and evaluated for nitrogen-fixing effectiveness in association with Medicago laciniata, M. littoralis, M. polymorpha, M. rugosa, M. tornata and M. truncatula. These symbiotic values were related to physical features of the environment, viz. soil type, soil reaction, mean annual rainfall, and the presence or absence and frequency of occurrence of sown and naturalised annual species of Medicago (medics). Large populations of S. meliloti (ranging from 270 to 460000 per gram of soil) were detected in 28 of the 29 soils where medics occurred. One or more species of medic were found in 29 of the 32 soils examined. The other 3 soils were relatively moist and acidic in reaction with a mean soil pH (CaCl 2 ) of 5.5. It could be inferred that the presence of populations of S. meliloti was dependent on the occurrence of species of Medicago. Other features of the environment had no impact on the size of S. melilotipopulations, except insofar as they influenced the occurrence of medics. All populations of S. meliloti were effective in nitrogen fixation for M. littoralis and M truncatula, the 2 species most commonly sown as legume components of the cereal–pasture farming systems of the Eyre Peninsula. Effectiveness of populations of S. meliloti for M. polymorpha, M. rugosa and M. tornata was significantly greater (P<0.05) in soils where M. polymorpha occurred than where it did not. Otherwise, the symbiotic capacity of the root-nodule bacteria was not influenced by soil type, soil pH, rainfall or the presence or absence of particular medics. There are many indications that medic productivity on the Eyre Peninsula is in decline with detrimental consequences for the nitrogen economy of the farming systems. The almost universal occurrence in soils of the Eyre Peninsula of large populations of S. meliloti that were effective for M. littoralis and M. truncatula indicated that, whatever the reasons for ‘medic decline’, the condition is not attributable to inadequacies of the naturally occurring populations of root-nodule bacteria.
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Herrero, E. V., J. P. Mitchell, W. T. Lanini, S. R. Temple, E. M. Miyao, R. D. Morse, and E. Campiglia. "Use of Cover Crop Mulches in a No-till Furrow-irrigated Processing Tomato Production System." HortTechnology 11, no. 1 (January 2001): 43–48. http://dx.doi.org/10.21273/horttech.11.1.43.
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No-till processing tomato (Lycopersicum esculentum Mill.) production in four winter cover crop-derived mulches was evaluated in 1997 and 1998 in Five Points, Calif. The effectiveness of two medics, `Sava' snail medic (Medicago scutellata Mill.) (sava), and `Sephi' barrel medic (Medicago truncatula Gaertn.) (sephi), and two cereal/legume cover crop mixtures, triticale/`Lana' woolypod vetch (X Triticosecale Wittm./Vicia dasycarpa Ten.) (triticale/vetch) and rye/`Lana' woolypod vetch (Secale cereale L./V. dasycarpa) (rye/vetch), was compared with two conventionally tilled fallow controls (with and without herbicide) (fallow+h and fallow-h) in suppressing weeds and maintaining yields with reduced fertilizer inputs. The comparison was conducted as a split plot, with three N fertilization rates (0, 100, and 200 lb/acre; 0, 112, and 224 kg·ha-1) as main plots and cover crops and fallow controls as subplots. Tomato seedlings were transplanted 3 weeks after the cover crops had been mowed and sprayed with herbicide. There were no significant differences in weed cover in the no-till cover crop treatments relative to the fallow controls in 1997. Early season weed suppression in rye/vetch and triticale/vetch plots was similar to herbicide-treated fallow (fallow+h) in 1998, however, later in the 1998 season weed suppression was best in the fallow+h. Tissue N was highest in the fallow treatments in both 1997 and 1998. Yields were highest in the triticale/vetch and fallow and lowest in sephi treatments in 1997, but there were no differences among treatments in 1998. These results demonstrate the feasibility of no-till mulch production of furrow irrigated processing tomatoes and identify opportunities for further optimization of the system.
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Henderson, CWL. "Sensitivity of eight cereal and legume species to the compaction status of deep, sandy soils." Australian Journal of Experimental Agriculture 31, no. 3 (1991): 347. http://dx.doi.org/10.1071/ea9910347.
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The effects of soil compaction and deep ripping on the growth and yield of crop (wheat, barley, oats, triticale, narrow leaf lupins and field peas) and pasture species (barrel medic and subterranean clover) were investigated for deep, sandy soils near Geraldton, Western Australia. In 1984 (an average rainfall season), growth and yields of all species were substantially reduced by soil compaction. Lupins were not included in the experiment. Barley, wheat and pea yields were reduced by around 45%; oat and triticale yields by 30%; and spring biomass of both pasture species was reduced by about 30%. The differences in response between the species were not significant (P>0.05). In 1985 (a very dry year), amelioration of soil compaction by deep ripping increased the dry matter at flowering of all the species, including lupins, by about 30%. Severe water stress in the cereals after flowering prevented the conversion of this dry matter advantage into grain yield differences. Because of late flowering and slow maturation, the yield of the oats was significantly (P<0.05) lower on the deep-ripped areas, compared with the yield on the compacted soil. Deep ripping increased the yield of peas by 60% and lupins by 20%, probably because flowering and seed filling were completed before the onset of severe water stress. For deep, sandy soils in mediterranean environments, maximum economic benefit would normally accrue from deep ripping prior to the cereal phase, given that current agronomic principles generally preclude the growing of peas on these soils. Selection of cereal species mainly depends on relative yields and prices; however, the results suggest that use of cultivars with rapid early growth, early flowering and quick maturity would maximise the response to compaction amelioration and minimise the risk of poor grain filling.
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Harris, R. H., M. J. Unkovich, and J. Humphris. "Mineral nitrogen supply from pastures to cereals in three northern Victorian environments." Australian Journal of Experimental Agriculture 46, no. 1 (2006): 59. http://dx.doi.org/10.1071/ea04177.
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An experiment at 3 sites (Birchip, Elmore and Speed) in the northern Victorian cropping belt compared dry matter (DM) production of short-term (2 year) pastures and their contributions to soil mineral nitrogen (N) and subsequent wheat and barley production. The pastures included different varieties of subterranean clover, annual medic and lucerne, and these were compared with ryegrass-dominant pasture, which represented the experimental control. More productive legume pastures generally resulted in greater accumulation of soil mineral N at sowing of the following cereal at both Elmore and Speed; however, at Birchip, soil mineral N remained high under all treatments. At Elmore and Speed, significant (P<0.10) positive relationships were observed between available N at sowing and subsequent wheat and barley production. Cereal grain yield at Birchip was not associated with available N at sowing. The quantities of soil mineral N available at sowing (152 kg/ha) of the cereals were in excess of crop demand at Birchip. At Elmore, the soil mineral N supply (83 kg/ha) was below that required for wheat and barley to reach their water-limited potential yield (20 kg grain/mm of growing season rainfall). However, at Speed, the supply of soil mineral N (63 kg/ha) was sufficient to achieve the water-limited potential grain yield and to produce malting-grade barley, but not sufficient to elevate wheat grain protein concentrations above 11.5%. In environments with low soil N levels, the amount of residual N following short-term pastures increased the availability of N to following cereals. Whether this is sufficient to satisfy subsequent crop demand is largely determined by water availability in the year of cropping. In cases where available N is already high, short-term pasture phases may have little effect on increasing crop production.
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McCallum, M. H., M. B. Peoples, and D. J. Connor. "Contributions of nitrogen by field pea (Pisum sativum L.) in a continuous cropping sequence compared with a lucerne (Medicago sativa L.)-based pasture ley in the Victorian Wimmera." Australian Journal of Agricultural Research 51, no. 1 (2000): 13. http://dx.doi.org/10.1071/ar99023.
Full textAbstract:
The nitrogen (N) dynamics (N2 fixation inputs, changes in soil mineral N and total N, N removed in agricultural produce) of a lucerne-based phase farming system (grazed lucerne–annual medic–ryegrass pastures grown in rotation with crops) was compared with that of continuous cropping (cereal, oilseed, and legume pulse crops) in the Victorian Wimmera. The contribution of biological N2 fixation to the N economy of these different systems was strongly linked to biomass production by the legume components of pastures, or field pea in the cropping sequence. The amount of fixed N present in field pea shoots or the total amount of N2 estimated to be fixed by the whole plant (shoots and roots) (121–175 kg N/ha.crop and 181–262 kg N/ha.crop, respectively) was generally greater than the combined measured annual inputs of fixed N by lucerne and annual medic during a pasture ley (40–95 kg N/ha.year in herbage, 80–190 kg N/ha.year in total plant), although large amounts of N were removed in the field pea grain at harvest (115–151 kg N/ha.crop). Over 2 years (1995–96), the seasonal rainfall patterns had a much larger impact on the growth, dry matter production, and N2 fixation of annual medic compared with lucerne. Winter-cleaning of ryegrass from the pasture before cropping resulted in a greater legume content in the pasture and generally increased amounts of fixed N in herbage (by up to 55 kg N/ha.year). Total soil N at depth (0.5–1.0 m) was significantly greater after 2–4 years of pasture than under continuous cropping. In one year (1996), the amount of soil mineral N following a winter-cleaned pasture was greater (by 32–45 kg N/ha, 0–1 m) than after either canola or wheat, producing a yield benefit in a subsequent canola crop that was equivalent to pre-drilling 46 kg N/ha as fertiliser. However, despite some improvements in N fertility, large crop responses to N fertiliser were still observed following pasture. Grain yield was increased by 0.33–0.55 t/ha in canola and by 1.0 t/ha in wheat, grain protein raised by 0.7–2.3% in canola and by 1.3% in wheat, and oil yield in canola enhanced by 124–205 kg/ha with pre-drilled applications of fertiliser N (46 kg/ha). It is speculated that more legume-dominant pastures (>80%) could provide greater flow-on N benefits to farming systems in the Wimmera than the mixed legume–grass swards used in the present study. However, it is likely that a need will remain for supplementary fertiliser N to optimise the nutrition of subsequent non-legume crops in the region.
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Dalal, R. C., W. M. Strong, E. J. Weston, J. E. Cooper, K. J. Lehane, and A. J. King. "Farming systems’ productivity and soil organic carbon stocks following fertilisers, no-tillage or legumes on a fertility-depleted soil in a semi-arid subtropical region." Soil Research 56, no. 4 (2018): 429. http://dx.doi.org/10.1071/sr17228.
Full textAbstract:
Depleted soil nitrogen supplies in long-term continuously cultivated soil for cereal grain cropping have resulted in reduced cereal yields, low grain proteins and hence low economic returns. This has necessitated the development of alternative management practices to sustain crop yields, as well as to restore and maintain soil fertility. In the present study we examined the comparative performance of several management options over a 12-year period, including: a 4-year rotation of grass + legume pasture followed by wheat (GL–wheat); 2-year rotations of lucerne–wheat, annual medic–wheat and chickpea–wheat; and continuous conventional tillage (CT) or no-tillage (NT), without or with fertiliser N application (0, 25 and 75 kg N ha–1 for each crop). Average wheat grain yields were highest in the chickpea–wheat rotation, followed by the NT wheat with 75 kg N ha–1; the lowest grain yields were in the CT or NT wheat treatment without fertiliser N application. Crop water use and gross margin were strongly correlated. However, there was an increasing potential for the deep leaching of nitrate-N at 75 kg N ha–1 application, as well as from the GL pasture initiated in 1987, but not from that initiated in 1986, emphasising the effect of variability in growing seasons. Soil organic C stocks increased under the 4-year GL pasture in the 0–0.1 m depth only, then decreased steadily following the cropping phase. The rotation of 4-year GL pasture followed by wheat cropping for 4–6 years may maintain initial soil organic C stock, but a shorter cropping phase is required to increase soil organic C and N stocks and soil fertility in the long term. Partial economic analysis of the treatments suggested that restoring or maintaining soil N fertility, either through legume-based pastures, grain legume and/or N fertiliser, provides long-term positive economic return.
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Abd El-Moneim, A. M., and P. S. Cocks. "Adaptation of Medicago rigidula to a cereal–pasture rotation in north-west Syria." Journal of Agricultural Science 107, no. 1 (August 1986): 179–86. http://dx.doi.org/10.1017/s0021859600066934.
Full textAbstract:
SUMMARYThe ley-farming system (integrated cereal and livestock production in which cerealsrotate with self-regenerating pastures) is considered to be of great potential benefit to north Africa and west Asia. In the colder parts of this region (of which north Syria is typical) its application is limited by poor adaptation of commercial medic cultivars (mainly Medicago truncatula and M. littoralis). An extended selection programme hag identified M. rigidula as adapted to the soils and climate of the region but nothing is known of its adaptation to the ley-farming system itself.An experiment which included 23 selections of M. rigidula and one each of M. rotata and M. noeana was conducted over 3 years during which herbage production, seed yield, and the fate of seeds were observed during the 1st year when pastures were established, the 2nd year when wheat was sown, and the 3rd year when the pasture regenerated. Of the 400–800 kg seed/ha produced in the 1st year an average of 87% remained in the soil in spring of the 3rd year. The weight of seed regenerating in the 3rd year varied from 30 to nearly 170 kg/ha, and herbage production, especially in winter, depended heavily on the number of regenerating seedlings. The most productive regenerating pastures produced nearly 2 t/ha of dried herbage by 1 January, and more than 6 t/ha for the whole growing season.The results showed that there was sufficient residual and newly produced seed at the end of the 3rd year to be sure that subsequent regeneration would result in similar herbage yields in the 5th year, and that the pasture was assured of long-term persistence. The significance of this for livestock production is discussed, and it is concluded that the results should encourage further investigation of grazing management and socioeconomic factors seen as constraints to introducing the ley-farming system to north Syria.
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Roesner, E. A., N. A. Fettell, and J. Brockwell. "Liming and choice of pasture species improve rhizobial persistence in an acidic chromosol (red-brown earth)." Australian Journal of Experimental Agriculture 45, no. 3 (2005): 247. http://dx.doi.org/10.1071/ea03153.
Full textAbstract:
An experiment was conducted to determine the persistence of soil root-nodule bacteria as influenced by different rates of lime and the previous pasture species. The work was done at Condobolin, central-western New South Wales, on a chromosol (red-brown earth), acidic in the upper profile (pHCa 4.6), which was representative of soils for an extensive region of the eastern Australian wheat belt. In autumn 1997, the experimental area was treated with 4 rates (6.0 t/ha, 3.0 t/ha, 1.5 t/ha, nil) of finely-ground agricultural limestone and sown with 5 pasture species: lucerne (Medicago sativa), barrel medic (M. truncatula), subterranean clover (Trifolium subterraneum), rose clover (T. hirtum) and ryegrass (Lolium rigidum). The pastures were removed with herbicide and cultivation in September 2000. The land lay fallow for 9 months and then was sown to wheat (Triticum aestivum) in autumn 2001 and again in autumn 2002. The most probable numbers of soil (0–10 cm) populations of the root–nodule bacterium for Medicago species (Sinorhizobium meliloti) and for the Trifolium species (Rhizobium leguminosarum bv. trifolii) were counted in May 2001 and May 2002. Soil pH, which was significantly (P<0.05) elevated 12 months after liming, declined substantially during the next 4 years although there was no concomitant decline in the pH of unlimed soil. The pasture species were highly productive of both pasture dry matter and nitrogen. The majority of legume pasture nitrogen was a consequence of symbiotic nitrogen fixation. There was a small but significant (P<0.05) dry matter response to application of lime in lucerne and barrel medic, and a larger nitrogen response to liming in lucerne, barrel medic and rose clover. Nitrogen fixation by rose clover appeared suboptimal. It was assumed from the density of plants that large populations of rhizobia developed in the soil during the growth of the legumes. Nine months after removal of the pasture, rhizobia numbers had fallen to low levels but did not fall further during the following year. The initial fall was attributed to high soil temperatures and low soil moisture during the Condobolin summer. The population of rhizobia for Trifolium species was about twice that of the rhizobia for Medicago species but the difference was not statistically significant. Liming had an overriding influence on the size of rhizobial populations, except in plots that had previously grown ryegrass where numbers remained low irrespective of rate of liming. Overall, most probable numbers escalated with each increase in rate of liming, from 10/g soil in the nil lime plots to 708/g in the 6 t/ha lime plots. The rhizobial homology of the pasture species (i.e. Sinorhizobium meliloti for the Medicago species and Rhizobium leguminosarum bv. trifolii for the Trifolium species) had an underlying but major influence on most probable numbers and in determining which rhizobial species occurred more commonly. Estimated populations of rhizobia in soils from homologous legumes were about 8 times those found in soils from non-homologous legumes. The benefits of applying lime to this red-brown earth soil may not have been merely a consequence of correction of low soil pH; increased levels of calcium may also have had a role. The results are discussed in relation to re-establishment of legume leys after the cereal phase of the cropping system.
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Yunusa, I. A. M., W. D. Bellotti, A. D. Moore, M. E. Probert, J. A. Baldock, and S. M. Miyan. "An exploratory evaluation of APSIM to simulate growth and yield processes for winter cereals in rotation systems in South Australia." Australian Journal of Experimental Agriculture 44, no. 8 (2004): 787. http://dx.doi.org/10.1071/ea03121.
Full textAbstract:
The Agricultural Production Systems Simulator (APSIM) suite of models was used to predict dynamics in water and nitrogen in soil, as well as the growth and yield of sequential crops of wheat and barley in pasture–wheat–barley rotations, between 1995 and 1997 at Roseworthy, South Australia. The NWHEAT model satisfactorily predicted above-ground dry matter, leaf area index and grain yields for both crops in rotations with either grassy (Grass) or medic (Medic) pastures, including the lack of significant response of yield to nitrogen fertiliser applied to wheat at sowing. Simulation data for soil water, from SOILWAT2, was consistent with measured data. Simulation with SOILN2, however, largely underestimated soil nitrogen, due to excessive uptake by the simulated wheat during the season when nitrogen was abundant and water supply readily available. Thus, the soil nitrate had to be reset at sowing for the following barley crop; simulated soil nitrate agreed with the measured data in this season when this nutrient was low. For most variables of crop growth and soil water, the simulated data were mostly within 2 standard errors of the measured means. Prediction of grain protein was underestimated in all cases, including where nitrogen in the shoot was overestimated. This was possibly due to inadequate remobilisation of nitrogen from the straw and roots to the grain by the simulated crop. A satisfactory prediction of dry matter, grain yield and grain weight was obtained for wheat when the models were extended to other trials at Roseworthy (Lower North), Minnipa (Upper Eyre Peninsula) and Wunkar (Murray Mallee), based on limited soil data. Long-term simulations of wheat yields showed that, with early sowing in the Lower North, median wheat yield increased by 50 kg/ha for every kilogram of nitrogen applied at sowing, up to a maximum nitrogen rate of 50 kg/ha. In the drier districts of the Upper Eyre Peninsula and the Murray Mallee, nitrogen fertiliser of no more than 25 kg/ha, applied at sowing, was enough to achieve yield benefits in any given season. At these drier sites, crop failures occurred in 5% (Upper Eyre Peninsula) and 10% (Murray Mallee) of the seasons simulated. Median sowing dates from these simulations were 15 May for the Lower North, 30 May for the Upper Eyre Peninsula and 24 May for Murray Mallee. This suggested that sowing could be conducted at least a week earlier than currently practised in the 3 environments. This study demonstrated the capability of APSIM to predict growth and grain yield of wheat and barley, as well as the associated dynamics of soil water in the main cereal belts of South Australia.
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Brandt, S. A. "Management practices for black lentil green manure for the semi-arid Canadian prairies." Canadian Journal of Plant Science 79, no. 1 (January 1, 1999): 11–17. http://dx.doi.org/10.4141/p97-091.
Full textAbstract:
Previous research with lentil (Lens culinaris Medic.) green manure in the semiarid prairies of western Canada has indicated that water use by the green manure crop often reduces grain yield of the succeeding cereal crop compared to those obtained after conventional summerfallow. In this study, we evaluated several green manure management practices that have potential to trap snow and enhance overwinter soil water recharge. These practices included: using herbicides to halt the growth of the green manure crop thus eliminating the need for soil incorporation, planting mustard (Sinapis alba L.) strips after incorporation, and leaving standing strips of non-incorporated lentil. Our results showed that none of the green manure management strategies increased wheat (Triticum aestivum L.) yield or grain protein concentration compared to wheat grown on conventional summerfallow. Leaving strips of standing lentil during bud stage incorporation provided barriers for wind erosion protection, while not decreasing wheat yield or protein content. Glyphosate or 2,4-D amine applied at bud stage of the lentil, and without soil incorporation, reduced available soil N. However, 2,4-D did not halt plant growth and water use quickly enough to avoid reducing yield of the succeeding wheat crop, while glyphosate generally halted water use more rapidly. The inability of the green manure management strategies to increase wheat yields over that obtained from conventional summerfallow was because the soil rooting zone is typically filled to capacity with water by this latter practice under the prevailing soil and climatic conditions. If green manuring is practised, early incorporation with lentil leave strips is the most promising management system. However, even with improved water management practices, green manuring did not demonstrate a consistent advantage over summerfallow, which may be required to offset the added economic costs required to enact this practice. Key words: Lens culinaris, legumes, summerfallow, soil nitrogen, soil water, wheat
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Armstrong, R. D., R. Perris, M. Munn, K. Dunsford, F. Robertson, G. J. Hollaway, and G. J. O. Leary. "Effects of long-term rotation and tillage practice on grain yield and protein of wheat and soil fertility on a Vertosol in a medium-rainfall temperate environment." Crop and Pasture Science 70, no. 1 (2019): 1. http://dx.doi.org/10.1071/cp17437.
Full textAbstract:
Fundamental changes in farming systems occurred throughout the medium-rainfall zone of southern Australia during the late 1990s. Pulse and canola crops replaced pastures and long-fallowing, and minimal-tillage practices were increasingly adopted. An experiment was established in 1998 to examine long-term effects of these changes on crop productivity and soil fertility. Nine rotation–tillage treatments based on 3- and 6-year cycles were compared by using wheat (Triticum aestivum) as a bioassay crop over 2001–17. Seasonal conditions during the study ranged from the Millennium Drought to the top rainfall decile. Averaged across the 17 seasons, wheat yields were significantly lower in rotations based on continuous wheat (1.73t/ha) or 3 years of perennial lucerne (Medicago sativa) (1.93t/ha) and highest after traditional long-fallow (2.92t/ha) or vetch (Vicia sativa) green manure (2.57t/ha). Wheat yields following a pulse (2.23t/ha) or canola (Brassica napus) (2.21t/ha) were intermediate. Whereas rotation effects varied with seasonal rainfall, there was a long-term trend for relative yields in continuous wheat rotations to decline and those following a green manure or fallow to differ increasingly from other treatments. Compared across the same rotation (canola–wheat–pulse), average wheat yields under no-tillage (2.09t/ha) were significant lower (P<0.05) than under reduced (2.22t/ha) and conventional (2.29t/ha) tillage. By contrast, grain protein concentration increased with increasing proportion and type of legumes (green manure and pasture>pulse) in the rotation via their effect on soil mineral nitrogen (N). Lowest protein was recorded in continuous wheat and highest where at least one-third of the rotation contained a non-pulse legume, i.e. vetch green manure, lucerne or annual medic (Medicago truncatula). Soil-borne cereal fungal pathogens and nematodes generally had little effect on grain yields. Soil organic carbon (SOC) and total N stocks declined in all treatments over time, except in the lucerne and green manure treatments, where total N was maintained. Greatest declines in SOC and total N occurred in the fallow treatment. Results from the first 20 years of experimentation suggest that differences in grain yield (and protein) of wheat were most likely the result of treatment (rotation and tillage practice) effects on soil nitrate and water (growing-season rainfall and fallow storage) rather than disease. We found no evidence that current farming systems based on use of pulses, canola and reduced tillage are less able to maintain intervening cereal yields than traditional systems. On the contrary, practices such as long-fallowing are expected to have increasing negative influence on productivity in the longer term via decreased soil C and N fertility.
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Dalal, R. C., E. J. Weston, W. M. Strong, K. J. Lehane, J. E. Cooper, G. B. Wildermuth, A. J. King, and C. J. Holmes. "Sustaining productivity of a Vertosol at Warra, Queensland, with fertilisers, no-tillage or legumes. 7. Yield, nitrogen and disease-break benefits from lucerne in a two-year lucerne - wheat rotation." Australian Journal of Experimental Agriculture 44, no. 6 (2004): 607. http://dx.doi.org/10.1071/ea02115.
Full textAbstract:
Continuous cultivation and cereal cropping of southern Queensland soils previously supporting native vegetation have resulted in reduced soil nitrogen supply, and consequently decreased cereal grain yields and low grain protein. To enhance yields and protein concentrations of wheat, management practices involving N fertiliser application, with no-tillage and stubble retention, grain legumes, and legume leys were evaluated from 1987 to 1998 on a fertility-depleted Vertosol at Warra, southern Queensland. The objective of this study was to examine the effect of lucerne in a 2-year lucerne–wheat rotation for its nitrogen and disease-break benefits to subsequent grain yield and protein content of wheat as compared with continuous wheat cropping.Dry matter production and nitrogen yields of lucerne were closely correlated with the total rainfall for October–September as well as March–September rainfall. Each 100 mm of total rainfall resulted in 0.97 t/ha of dry matter and 26 kg/ha of nitrogen yield. For the March–September rainfall, the corresponding values were 1.26 t/ha of dry matter and 36 kg/ha of nitrogen yield. The latter values were 10% lower than those produced by annual medics during a similar period. Compared with wheat–wheat cropping, significant increases in total soil nitrogen were observed only in 1990, 1992 and 1994 but increases in soil mineralisable nitrogen were observed in most years following lucerne. Similarly, pre-plant nitrate nitrogen in the soil profile following lucerne was higher by 74 kg/ha (9–167 kg N/ha) than that of wheat–wheat without N fertiliser in all years except 1996. Consequently, higher wheat grain protein (7 out of 9 seasons) and grain yield (4 out of 9 seasons) were produced compared with continuous wheat. There was significant depression in grain yield in 2 (1993 and 1995) out of 9 seasons attributed to soil moisture depletion and/or low growing season rainfall. Consequently, the overall responses in yield were lower than those of 50 kg/ha of fertiliser nitrogen applied to wheat–wheat crops, 2-year medic–wheat or chickpea–wheat rotation, although grain protein concentrations were higher following lucerne.The incidence and severity of the soilborne disease, common root rot of wheat caused by Bipolaris sorokiniana, was generally higher in lucerne–wheat than in continuous wheat with no nitrogen fertiliser applications, since its severity was significantly correlated with plant available water at sowing. No significant incidence of crown rot or root lesion nematode was observed. Thus, productivity, which was mainly due to nitrogen accretion in this experiment, can be maintained where short duration lucerne leys are grown in rotations with wheat.
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Kaiser, A. G., B. S. Dear, and S. G. Morris. "An evaluation of the yield and quality of oat - legume and ryegrass - legume mixtures and legume monocultures harvested at three stages of growth for silage." Australian Journal of Experimental Agriculture 47, no. 1 (2007): 25. http://dx.doi.org/10.1071/ea05221.
Full textAbstract:
The effect of harvest time on the dry matter (DM) yield and quality of 10 annual temperate legumes [Trifolium subterraneum, var. brachcalycinum and var. subterraneum L. (subterranean clover), T. michelianum Savi (balansa clover), T. alexandrinum L. (berseem clover), Medicago murex Willd. (murex medic), M. truncatula Gaertn. (barrel medic), T. vesiculosum Savi (arrowleaf clover), Vicia sativa L. (common vetch), V. benghalensis L. (purple vetch), Pisum sativum L. (peas) grown in monoculture or in mixtures with oats (Avena sativa L.)] was examined in a Mediterranean environment in southern New South Wales. Three of the legumes (subterranean clover, berseem and peas) were also grown in mixtures with ryegrass (Lolium multiflorum Lam.). The forages were sown on 29 May and harvested at three times (2 October, 23 October and 6 November), corresponding to the boot, anthesis and dough stage of the cereal oat variety, Kalgan. Peas were the highest yielding of the legume monocultures at each of the three harvest times (6.9, 11.6, 12.3 t DM/ha), followed by purple vetch (6.2, 9.9, 8.7 t DM/ha). Of the small-seeded pasture legumes, berseem, murex and arrowleaf clover were the highest yielding at the second harvest (7.5–8.8 t DM/ha) when most reached their peak biomass. The inclusion of oats with the legumes increased total DM yield at the first, second and third harvests by 10–54, 7–99 and 3–102%, respectively. Oat monocultures were high yielding (up to 17.7 t DM/ha), but had low N contents (6.3–12.5 g N/kg DM). Oat–legume forage mixtures had nitrogen (N) contents of 7–15 g N/kg compared with 17–40 g N/kg in the legume monocultures. The N content and digestibility of most species and mixtures decreased as harvest time was delayed, whereas total DM peaked at the second harvest for all species except Cooba oats. The legume content of the mixtures was negatively correlated with total DM yield, DM content and water soluble carbohydrates, but positively correlated with N content, in vitro digestibility and buffering capacity. The digestibility of oats decreased more rapidly than the legumes with advancing maturity, and it would need to be harvested at the boot stage to produce a silage of sufficiently high metabolisable energy for the production feeding of cattle. A later harvest at anthesis when yield is higher would produce a silage of sufficient quality for production feeding from an oat–large seeded legume mixture with a legume content of 0.50. The oats and ryegrass had high water soluble carbohydrate and low to medium buffering capacity and would, therefore, be expected to produce well-preserved silages. The legume monocultures had low water soluble carbohydrate contents and high buffering capacity values and there would be a high risk of a poor silage fermentation in these forages without field wilting or the use of a silage additive.
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Bell, Lindsay W., John Lawrence, Brian Johnson, and Mark B. Peoples. "New ley legumes increase nitrogen fixation and availability and grain crop yields in subtropical cropping systems." Crop and Pasture Science 68, no. 1 (2017): 11. http://dx.doi.org/10.1071/cp16248.
Full textAbstract:
Several new and existing short-term forage legumes could be used to provide nitrogen (N) inputs for grain crops in subtropical farming systems. The fixed-N inputs from summer-growing forage legumes lablab (Lablab purpureus), burgundy bean (Macroptilium bracteatum) and lucerne (Medicago sativa) and winter-growing legume species snail medic (Medicago scutellata), sulla (Hedysarum coronarium) and purple vetch (Vicia benghalensis) were compared over several growing seasons at four locations in southern Queensland, Australia. Available soil mineral N and grain yield of a following cereal crop were compared among summer-growing legumes and forage sorghum (Sorghum spp. hybrid) and among winter-growing legumes and forage oats (Avena sativa). In the first year at all sites, legumes utilised the high initial soil mineral N, with <30% of the legume N estimated to have been derived from atmospheric N2 (%Ndfa) and legume-fixed N <30 kg/ha. In subsequent years, once soil mineral N had been depleted, %Ndfa increased to 50–70% in the summer-growing legumes and to 60–80% in winter-growing legumes. However, because forage shoot N was removed, rarely did fixed N provide a positive N balance. Both lablab and burgundy bean fixed up to 150 kg N/ha, which was more than lucerne in all seasons. Prior to sowing cereal grain crops, soil nitrate was 30–50 kg/ha higher after summer legumes than after forage sorghum. At one site, lablab and lucerne increased the growth and yield of a subsequent grain sorghum crop by 1.4 t/ha compared with growth after forage sorghum or burgundy bean. Of the winter-growing legumes, sulla had the highest total N2 fixation (up to 150 kg N/ha.year) and inputs of fixed N (up to 75 kg N/ha), and resulted in the highest concentrations of soil N (80–100 kg N/ha more than oats) before sowing of the following crop. Wheat protein was increased after winter legumes, but there was no observed yield benefit for wheat or grain sorghum crops. New forage legume options, lablab, burgundy bean and sulla, showed potential to increase N supply in crop rotations in subtropical farming systems, contributing significant fixed N (75–150 kg/ha) and increasing available soil N for subsequent crops compared to non-legume forage crops. However, high soil mineral N (>50 kg N/ha) greatly reduced N2 fixation by forage legumes, and significant N2 fixation only occurred once legume shoot N uptake exceeded soil mineral N at the start of the growing season. Further work is required to explore the impact of different management strategies, such as livestock grazing rather than harvesting for hay, on the long-term implications for nutrient supply for subsequent crops.
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Mclaughlin, MJ, and AM Alston. "The relative contribution of plant residues and fertilizer to the phosphorus nutrition of wheat in a pasture cereal system." Soil Research 24, no. 4 (1986): 517. http://dx.doi.org/10.1071/sr9860517.
Full textAbstract:
Wheat plants (Triticum aestivum cv. Warigal) here grown in a solonised brown soil (Calcixerollic xerochrept) which had been previously cropped to medic (Medicago trunculata cv. Paraggio). The 33P-labelled medic residues and 32P-labelled monocalcium phosphate were added to the soil in factorial combination. Amounts of 31P, 32P and 33P in the wheat plants and in the soil microbial biomass were determined. Addition of residues depressed wheat dry weight, 31P and 32P uptake, while simultaneously increasing amounts of 31P and 32P incorporated into the microbial biomass. Addition of fertiliser had no effect on the proportion of plant P taken up from the residues, but significantly increased the proportion of microbial P derived from this source. The 31P held in the microbial biomass was significantly increased by both residue and fertiliser P addition, with the former having the larger effect. Of the total P applied to the soil, medic residues contributed approximately one-quarter of that supplied by the fertiliser. Of the total P in the wheat plant, medic residues supplied approximately one-fifth of that supplied by the fertiliser.
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Christiansen, S., A. M. Abd El Moneim, P. S. Cocks, and M. Singh. "Seed yield and hardseededness of two amphicarpic pasture legumes (Vicia sativa ssp. amphicarpa and Lathyrus ciliolatus) and two annual medics (Medicago rigidula and M. noeana)." Journal of Agricultural Science 126, no. 4 (June 1996): 421–27. http://dx.doi.org/10.1017/s002185960007550x.
Full textAbstract:
SUMMARYYields and hardseed breakdown of underground and aerial seeds in subterranean vetch (Vicia sativa ssp. amphicarpa) and lathyrus (Lathyrus ciliolatus) and aerial seeds of Medicago rigidula and M. noeana were compared at Tel Hadya, near Aleppo, in north Syria between 1990 and 1992. Underground and aerial seed and straw (mature herbage) yields were measured at maturity in the first spring, and hardseed breakdown over the following summer, autumn and winter. Regenerating herbage production was measured in the second spring.In the establishment year (292 mm rainfall) the medics produced twice as much straw as the amphicarpic species. In contrast, seed yields were less than half: M. rigidula and M. noeana produced 412 and 110 kg/ha respectively, while subterranean vetch and lathyrus produced 1174 and 736 kg/ha. More than 95 % of the total seed yield of the amphicarpic legumes was underground. Underground seeds of the amphicarpic legumes were larger than aerial seeds, and almost 10 times as large as the medic seeds.Seeds of all species were > 90% hard when newly set in summer. At the first seasonal rains > 95% of underground seed had softened, compared with 5 and 40% of the aerial seeds of vetch and lathyrus respectively. The medics remained > 90% hardseeded. In laboratory tests, embryo dormancy was observed in all species prior to the onset of first seasonal rains. For the amphicarpic legumes, but not for the medics, embryo dormancy persisted into winter. In the field, and after all germination events, 900–1430 seeds/m2 of subterranean vetch seed remained in the soil. This was considerably more than expected, based on the low levels of hardseededness and embryo dormancy observed in the laboratory. The results suggest that dormant seeds of the amphicarpic legumes need light to germinate.In the second year (353 mm rainfall), regenerating M. rigidula produced 5·3 t/ha compared with 3·4 t/ha by the best subterranean vetch from approximately equal numbers of seedlings. The amphicarpic legumes germinated later and over a more extended period than the medics, indicating that they could become weeds in a cereal/pasture rotation. However, the results suggest that in drier areas or in drier years the vetches will compare favourably with the medics in most respects. Clearly, subterranean vetch and lathyrus have great potential for pasture improvement in dry areas.
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Brandt, S. A. "Alternatives to summerfallow and subsequent wheat and barley yield on a Dark Brown soil." Canadian Journal of Plant Science 76, no. 2 (April 1, 1996): 223–28. http://dx.doi.org/10.4141/cjps96-041.
Full textAbstract:
A number of alternative options to summerfallow are feasible on the Dark Brown soils of the Canadian prairies. These include recropping to cereal or pulse crops, as well as use of summerfallow substitute crops, such as legume green manures. The objective of this study was to evaluate these options for their impact on the productivity of subsequent crops. Green-manure lentil (Lens culinaris Medic.), incorporated at either the bud or full-bloom stage of growth, field pew (Pisum sativum L.), grain lentil, and wheat (Triticum aestivum L.) grown as grain were compared with conventional summerfallow for their impact on yield of a succeeding wheat crop and of barley (Hordeum vulgare L.) grown the year after wheat on a Dark Brown Chernozemic soil at Scott, Saskatchewan. During the 5-yr period, 1984–1988, above-ground dry-matter production of green-manure lentil averaged 500 kg ha−1 at the bud stage of growth but more than doubled to 3170 kg ha−1, by full bloom. Grain yield of field pea averaged 1470 kg ha−1, while that of grain lentil, unfertilized wheat, and N-fertilized wheat averaged 1220, 1290 and 1490 kg ha−1, respectively. Considerable year-to-year yield variation occurred with all crops, variability being greatest for lentil. Yield of wheat grown after lentil green manure was similar to yield of wheat on summerfallow (2340 kg ha−1) during each of the 5 yr for both early (2360 kg ha−1) and late (2250 kg ha−1) incorporation. Wheat yield after pea (2210 kg ha−1) or grain lentil (2080 kg ha−) was reduced in 1987, but it was equal to wheat yield after summerfallow during the remaining 4 yr. Yield of wheat on wheat stubble, whether fertilized with N (1830 kg ha−1) or not (1610 kg ha−1), was generally lower than on summerfallow. Yield of barley grown the following year was generally unaffected by summerfallow or summerfallow substitute treatments. The higher value and similar productivity of pea and grain lentil, compared with wheat, combined with their favourable impact on subsequent wheat yield, should make these crops attractive alternatives to summerfallow. On fields unsuited to pea or grain lentil production, lentil green manures may be a suitable alternative to summerfallow because they should reduce soil degradation, although lentil green manures leave little residue to protect against soil erosion where through incorporation is practised. Summerfallow or green manure incorporated early or late generally resulted in greater available soil water and N for a succeeding crop than did grain lentil, pea or wheat. Key words: Green manuring, legume effect, recropping, lentil, grain yield, summerfallow alternatives