Proportion Of Legumes Research Articles

Dietary Contributors to Food Group Intake in Preschool Children Attending Family Childcare Homes

Abstract Objectives To identify and describe the food sources that contribute to food group intake in preschool children attending family childcare homes (FCCH) in Rhode Island and to examine differences by provider ethnicity. Methods Baseline data (n = 120 FCCH and n = 370 children) from Healthy Start, an ongoing cluster-randomized trial, were used. Information about foods and beverages consumed by the children was collected using the Dietary Observation in Child Care. The Nutrition Data System for Research food group classification was used to define food groups, sources and servings. The contribution of food sources to major food groups was calculated using ratio of means. Differences in mean ratios between Latino and non-Latino providers were tested with ANOVA and ANCOVA (P < 0.05) and Bonferroni adjustments were made for multiple comparisons. Results The analysis included 120 FCCH providers, all female, 68% were Latino, mean age of 48.9 ± 9.0 years; and 370 preschool children, 57% were Latino, mean age of 3.4 ± 0.9 years. Across FCCH, juice contributed the highest proportion to the fruits consumed (0.85 ± 0.24), and most vegetables consumed were non-starchy (0.61 ± 0.34). Nearly, three-fourths of dairy was low-fat (0.71 ± 0.30) and most milk/yogurt was unsweetened (0.85 ± 0.20). Three fourths of the grain servings consumed were refined (0.75 ± 0.22). The majority of the fats were vegetable oils (0.89 ± 0.20), and syrup/honey/jelly contributed more than half (0.50 ± 0.41) to the total sweets consumed. Children in non-Latino vs Latino FCCH consumed a significantly higher proportion of nuts and seeds (0.21 ± 0.34 vs 0.05 ± 0.13) and animal fats (0.37 ± 0.36 vs 0.11 ± 0.20). Similarly, children attending non-Latino FCCH ate a significantly higher proportion of non-starchy vegetables (0.82 ± 0.24 vs 0.52 ± 0.34), but a significantly lower proportion of legumes (0.05 ± 0.19 vs 0.33 ± 0.31) compared to Latino FCCH. Conclusions FCCH providers should be encouraged to include more whole fruits and whole grains. Differences between the foods consumed in FCCH according to the ethnicity of the provider, highlights the importance of considering cultural differences when developing tailored interventions to improve children's dietary intake at these settings. Funding Sources National Institutes of Health- National Heart, Lung, Blood Institute, National Institutes of Health.

Grain legume-cereal intercropping enhances the use of soil-derived and biologically fixed nitrogen in temperate agroecosystems. A meta-analysis

Abstract Grain legumes are known for their benefits to deliver ecosystem services on provisioning of protein-rich food and feed, reducing greenhouse gas emissions through the symbiotic nitrogen fixation function and diversification of cropping systems. Intercropping is an agroecological practice in which two or more crop species are grown simultaneously in the same field, thereby maximizing the use of resources to enhance yields in low input systems and the resilience of cropping systems. We quantified the effect of grain legume-cereal intercropping on the use of N resources in temperate agroecosystems, focusing on dinitrogen (N2) fixation and soil-derived nitrogen acquisition using a meta-analysis of 29 field-scale studies. We estimated and compared effects of different intercrop compositions (proportion of each species in the intercrops), fertilization rates, crop species, soil properties, and other management practices on the symbiotic N2 fixation and the acquisition of soil-derived nitrogen by the cereals and grain legumes. The proportion of N derived from N2 fixation was on average 14 % (95 % CI = [11, 16]) higher in intercropped grain legumes (76 %) compared to legume sole crops (66 %). On the other hand, intercropping reduced the amount of N2 fixed (kg ha−1) by about 15 %, when N2 fixation in inter- and sole cropped legumes was expressed at equivalent density by compensating for the sown legume proportion in intercrops relative to their sole crop sowing rate. The results were mainly influenced by the intercrop composition, legumes species and the method used to quantify N2 fixation. Soil-derived nitrogen acquisition in intercropped grain legumes was significantly reduced (−47 %, 95 % CI = [−56, −36]) compared to sole crop legumes, expressed at equivalent density, while the soil N acquired by intercropped cereals was much higher (+61 %, 95 % CI = [24, 108]) than in sole crop cereals. Total soil N acquisition (legume + cereal) was significantly higher in intercrops than in legume sole crops (+25 %, 95 % CI = [1, 54]), while there was no significant difference between intercrops and cereal sole crops. The meta-analysis confirms and highlights that intercropping consistently stimulates complementary N use between legumes and cereals by increasing N2 fixation by grain legumes and increasing soil N acquisition in cereals. Based on the results of this analysis it would be suggested that cropping systems diversification via intercropping can be used for simultaneous production of both cereals and grain legumes, while increasing the use of N-sources and reducing external inputs of N fertilizers, thereby enhancing the sustainability of agriculture.

Defoliation frequency affects litter responses and nitrogen excretion by heifers in palisadegrass–forage peanut pastures

AbstractLegumes can contribute significantly to nitrogen (N) input in grazing systems. Grazing management is a critical factor affecting N cycling in mixed pastures, altering the legume N input as a result. This study assessed how defoliation frequency affects N cycling in rotationally stocked palisadegrass (Brachiaria brizantha) and forage peanut (Arachis pintoi) pastures. Treatments included four grazing management strategies, defined by the rest period interruption when the canopy reached 90 (90LI), 95 (95LI), and 100% (100LI) of photosynthetically active radiation interception (LI), and a fixed rest period of 42 d (42D). A 2‐yr experimental period was adopted. Existing litter was greater at 100LI (2208 vs. 1964 kg ha−1; average of 42D, 90LI, and 95LI, respectively). Greater defoliation frequency (42D and 90LI) resulted in increase of litter legume proportion, resulting in greater decomposition rate, lower litter half‐life (p < .001, and p = .015, respectively), and greater N cycling (91 vs. 64 kg ha−1 season−1). Less frequent defoliation (100LI) resulted in reduced total forage intake, proportion of legume intake, and lower N intake compared with other treatments (p = .007, p = .081, and p < .001, respectively). Greater defoliation frequency increased N cycling via litter, but did not affect excretion due to compensation with stocking rate. Defoliation frequency between 90 and 95% LI optimizes N cycling in palisadegrass‐forage peanut mixed pastures.

Soil-geomorphology relationships determine the distribution of the main subalpine grasslands in the Central Pyrenees (NE-Spain)

The two most widely extended mountain grasslands in Europe (Nardus-mat grasslands and chalk grasslands) are distributed forming complex patterns. In the Ordesa and Monte Perdido National Park (Central Pyrenees, NE-Spain), they grow as secondary pastures within the treeline ecotone at the subalpine belt. This work aims to show the influence of soil properties on the spatial distribution of these pastures, under a dynamic geomorphology. Soils are sampled under both grasslands, which grow on different cumulative levels: Nardus-mat grasslands in the upper level (L1) and chalk grasslands in the lower level (L2). Soils in L1 have a significantly higher acidity, lower soluble ions and exchangeable calcium content than those in L2, reflecting a more intense leaching process, consistent with a longer period of slope stability. Qualitative differences are detected in the soil organic matter of the soil, using carbon and nitrogen isotopes, lighter in L2 soils than in L1 soils, due to a higher proportion of legumes growing in L2 (chalk grasslands). Soils in L1 and L2 shared many physical properties, such as a fine and homogeneous texture in the whole profile (silty clay or silty clay loam), and high aggregate stability and porosity in the topsoil. In contrast, the soils in L2 are shallower than in L1, which reduces their water-holding capacity. The soil is classified as Orthoeutric Cambisol (Clayic, Humic) in L1 but its rejuvenation, by gully erosion, transforms it into an Hypereutric Leptosol (Loamic, Ochric) in L2 (Typic Haplocryept and Lithic Haplocryept, respectively by Soil Taxonomy system). Definitely, the distribution of both grasslands for the studied area is linked to two cumulative levels of different ages, which in turn is strongy related to different soil properties.

Maize and dietary change in early Peruvian civilization: Isotopic evidence from the Late Preceramic Period/Initial Period site of La Galgada, Peru

The Late Preceramic Period (3000–1700 BCE) and Initial Period (1700–800 BCE) in Peru was a time of emergent social complexity as illustrated by the construction of ceremonial architecture and permanent settlements. A long-standing debate centers on the nature of the subsistence economies that supported this incipient complexity. Though some scholars consider maize to have been an agricultural staple at this time, a growing body of archaeological research indicates that the use of maize spread irregularly throughout Peru and did not become a dietary staple until sometime after c. 800 cal BCE. Using stable isotope analysis (δ13C and δ15N) of human bone and dentine, together with radiocarbon dating, this study estimates dietary composition, as well as changing subsistence strategies among 32 individuals interred within the ceremonial center of La Galgada (2300–1300 cal BCE). Our data suggests that maize was not a dietary staple in either the Late Preceramic or the Initial (1700–800 cal BCE) Period occupations at La Galgada. Instead the modeled diet (SIAR Mixing Model) suggests a continued reliance on locally available food sources (i.e. primarily C3, legumes and grazing fauna). This finding combined with archaeological evidence indicates that diet remained relatively similar during the site’s occupation. Three radiocarbon dates generated for this study also indicate the re-use of La Galgada as a cemetery during the Late Intermediate Period (LIP) (1150–1450 cal CE). Diet during the LIP exhibits a significant change, with a decrease in the proportion of C3 and legumes and an increase in the proportion of meat. This study highlights the utility of mixing models to reconstruct past human diet, allowing for a more comprehensive understanding of potential differences in the proportions of food types over time.

Sward composition and soil moisture conditions affect nitrous oxide emissions and soil nitrogen dynamics following urea-nitrogen application

Increased emissions of N2O, a potent greenhouse gas (GHG), from agricultural soils is a major concern for the sustainability of grassland agriculture. Emissions of N2O are closely associated with the rates and forms of N fertilisers applied as well as prevailing weather and soil conditions. Evidence suggests that multispecies swards require less fertiliser N input, and may cycle N differently, thus reducing N loss to the environment. This study used a restricted simplex-centroid experimental design to investigate N2O emissions and soil N cycling following application of urea-N (40 kg N ha−1) to eight experimental swards (7.8 m2) with differing proportions of three plant functional groups (grass, legume, herb) represented by perennial ryegrass (PRG, Lolium perenne), white clover (WC, Trifolium repens) and ribwort plantain (PLAN, Plantago lanceolata), respectively. Swards were maintained under two contrasting soil moisture conditions to examine the balance between nitrification and denitrification. Two N2O peaks coincided with fertiliser application and heavy rainfall events; 13.4 and 17.7 g N2O-N ha−1 day−1 (ambient soil moisture) and 39.8 and 86.9 g N2O-N ha−1 day−1 (wet soil moisture). Overall, cumulative N2O emissions post-fertiliser application were higher under wet soil conditions. Increasing legume (WC) proportions from 0% to 60% in multispecies swards resulted in model predicted N2O emissions increasing from 22.3 to 96.2 g N2O-N ha−1 (ambient soil conditions) and from 59.0 to 219.3 g N2O-N ha−1 (wet soil conditions), after a uniform N application rate. Soil N dynamics support denitrification as the dominant source of N2O especially under wet soil conditions. Significant interactions of PRG or WC with PLAN on soil mineral N concentrations indicated that multispecies swards containing PLAN potentially inhibit nitrification and could be a useful mitigation strategy for N loss to the environment from grassland agriculture.

Plant Nitrogen and Phosphorus Resorption in Response to Varied Legume Proportions in a Restored Grassland.

An in-depth assessment of plant nutrient resorption can offer insights into understanding ecological processes and functional responses to biotic and abiotic changes in the environment. The legume proportion in a mixed grassland can drive changes in the soil environment and plant relationships, but little information is available regarding how the legume proportion influences plant nutrient resorption in mixed grasslands. In this study, three mixed communities of Leymus chinensis (Trin.) Tzvel. and Medicago sativa L. differing in legume proportion (Low-L, with 25% legume composition; Mid-L, with 50% legume composition; High-L, with 75% legume composition) were established with four replicates in a degraded grassland. Four years after establishing the mixed grassland, the quantity of biological N2 fixation by M. sativa, the availabilities of water and nitrogen (N) and phosphorus (P) in soil were examined, and the concentrations and resorption of leaf N and P for both species were measured during forage maturation and senescence. The results showed Mid-L had greater biological N2 fixation and soil N availability than Low-L and High-L, while the High-L had lower soil water and P availability, but a greater soil available N:P ratio compared with Low-L and Mid-L. Legume proportion did not alter N or P concentrations of mature leaves. However, in Mid-L N resorption was reduced by 8 to 16% for the two mixed-species compared with Low-L and High-L. High-L enhanced P resorption by 20 to 24% in both plant species compared with Low-L. The L. chinensis and M. sativa responded differently to varied legume proportion in terms of P resorption. It was concluded that legume proportion drove changes in soil nutrient availability of mixed communities, which primarily altered plant nutrient resorption during senescence, but had no influence on the nutrient concentrations of mature plants. A moderate legume proportion reduced N resorption, and increased senesced leaf N concentration of grass and legume species. The difference in P resorption by two mixed-species significantly changed the interspecific difference of senesced leaf P concentration and the N:P ratio with varied legume proportion.

Biochar shifts biomass and element allocation of legume-grass mixtures in Cd-contaminated soils.

Biochar amendments have been considered to increase the competitive abilities of legumes in mixed cultures. However, little is known about how biochar affects the nutrient and Cd allocation within legume-grass mixtures. Therefore, we conducted a pot experiment to explore the effects of biochar addition rate (0, 1, 2.5, and 5%) on four monocultures, the legume Trifolium repens (Tr), Lolium perenne (Lp), Dactylis glomerata (Dg) and Festuca arundinacea (Fa), and three mixed cultures, i.e., Tr + Lp, Tr + Lp + Dg, and Tr + Lp + Dg + Fa. Regardless of biochar addition, Tr plants showed the lowest aboveground Cd concentration among the monoculture treatments. Compared with non-biochar addition treatment, the 1% biochar addition significantly promoted aboveground biomass accumulation and P, K, Ca, and Mg uptake in the aboveground parts of the Tr monoculture treatments by 39.32, 39.88, 88.27, 69.68, and 51.96%, respectively. Nevertheless, the aboveground biomass and P, K, Ca, and Mg uptake as well as the proportion of these parameters in Tr plants in all plant species mixture treatments decreased after biochar application. Maximum aboveground P and Mg uptake occurred in the four-species mixture treatments without biochar addition, whereas maximum values of these parameters occurred in the three-species mixture treatments with 5% biochar addition. Shoot Cd uptake was not decreased by biochar addition at all plant species treatments. Based on the results, it was suggested that biochar could not reduce Cd uptake by increasing the proportion of legumes in the legume-grass mixtures. The complementarity effects on nutrient uptake in the plant species mixtures depended on the amount of biochar added.

Растительные сукцессии на отвалах угольных шахт в лесостепи Тульской области

The paper describes vegetation successions that can be observed on waste piles of Moscow lignite basin. Characterization of succession are performed with geobotanical descriptions that were made at non-recultivated waste pile, levelled dump and phytomeliorated waste pile. ^lonization of coal waste piles by plants corresponds to primary succession that proceeds in specific edaphic conditions. Term and trajectory of this process on waste piles of Moscow lignite basin in the Tula oblast differ at various object types. The rate of revegetation is slowest at slopes of waste piles and levelled spoils, where only solitary individuals of ruderal species can occur. At levelled spoils’ surfaces and self-developing deluvial-proluvial foreslopes (which is forming at waste pile foot) pioneer plant groups, simple structured phytocoenoses and complex structured phytoco-enoses are discovered. Most common tree species in simple structured and complex structured communities is Betula pendula. Under the toxic flow influence herbaceous layer at deluvial-proluvial foreslopes and in certain parts of levelled spoil consists mainly of Calamagrostis epigeios, Equisetum spp., Convolvulus arvensis. Out of toxic flow influence at levelled spoil forb meadows with large proportion of legumes (Trifolium hybridum, Lotus corniculatus, Melilotus albus etc.) occur. Succession stages changing is not rapid and revegetation processes takes decades; the phytomelioration of Moscow lignite basin waste piles in the Tula oblast can speed this process up by overcoming the delayed pioneer plant groups stage. The pattern of plant succession trajectories on waste piles of Moscow lignite basin in forest-steppe landscapes of the north part of the Central Russian Upland was developed.

Effects of lime, phosphorus and stocking rate on an extensively managed permanent pasture: botanical composition and groundcover

Low phosphorus (P) constrains productivity of many of the permanent pastures of south-eastern Australia where wool and meat production are important. Whereas the need for fertilisation with P is indisputable for many soils, the benefits of liming to ameliorate soil acidification are not always clear in terms of forage production or quality. This experiment, by measuring botanical composition and groundcover over 10 years, aimed to address the issue of forage composition and groundcover. Merino wethers were continuously grazed on a permanent pasture under two stocking rates (low and high) following treatments with three rates of surface-applied lime and two rates of P. The lime rates were: nil, and sufficient to raise the pHCaCl2 of the 0–10 cm soil layer to 5.0 and to 5.5. Phosphorus was added as two rates of single superphosphate: 125 kg ha–1 every 2–3 years, and 250 kg ha–1 every year. Two hypotheses were proposed: (i) as lime application rate increased, it would lead to the pasture swards having a higher percentage of species favourable for grazing animal production, and a higher level of sward groundcover would be maintained; and (ii) legume presence would be favoured by a higher level of applied P over the long term. The Millennium Drought (1997–2008), which coincided with this experiment (1998–2008), tended to mask or reduce lime effects; nevertheless, the higher legume content in the sward, as well as the superior groundcover found in the high lime–high P treatments at various times throughout the experiment and at its completion compared with the nil-lime control, indicated positive forage effects of lime application. Moreover, by the termination of the experiment in 2008, groundcover generally tended to be lower under nil lime than in treatments that had received lime. The higher proportion of legume in the sward was closely linked to greater applied P, although this did not occur at the low stocking rate in the absence of lime. By contrast, similar high P–low stocking rate treatments but with applied lime had the highest clover contents. It is proposed that the poor persistence of the treatment without lime may be due to a combination of poor legume seedset, because of excessive competition from accompanying grasses, and aluminium toxicity adversely affecting legume growth.

Positive legacy effect of previous legume proportion in a ley on the performance of a following crop of Lolium multiflorum

AimsWe investigated the legacy effects of a previous ley’s legume proportion on the performance of a following grass crop in a rotation.MethodsIn April 2015, a pure Lolium multiflorum L. crop was sown after the removal of legume containing swards (0–100% legumes), and was harvested four times over the following one-year period (3 times in 2015 and once the following April 2016). Labeled 15N fertilizer (50 kg N ha−1) was applied during the 2nd and 3rd re-growth periods to determine N fluxes.ResultsAcross the one-year period, a significant legume-legacy induced increase in biomass yield of L. multiflorum was observed over the entire range of previous legume proportions when compared against the non-legume ley, the effect being 2.15 and 1.73 t ha−1 (P ≤ 0.001 each) in swards with 50% and 100% previous legume proportion, respectively, or up to +31%. The legume-legacy effect on biomass yield was most pronounced at the 1st harvest (June) and persisted into the 2nd harvest in August (P ≤ 0.05 both, over the entire range of previous legume proportion), though was no longer evident at the 3rd harvest (September). Importantly, the legume-legacy effect returned in the 4th harvest in April (P ≤ 0.05). Examining the source of N contributing to N yield confirmed that more N was derived from the soil at harvest 1 and 2 for previous legume containing leys (P ≤ 0.001) compared to those which contained no legumes, with a significant increase still seen for legume mixtures at harvest 3 (P ≤ 0.01).ConclusionsThe results demonstrate a sustained soil-transferred performance-enhancing legacy effect on a following crop in a rotation, with previous legume proportions of 50% having a comparable effect compared with that of a previous legume monoculture.

Production of beef cattle grazing on Brachiaria brizantha (Marandu grass)—Arachis pintoi (forage peanut cv. Belomonte) mixtures exceeded that on grass monocultures fertilized with 120 kg N/ha

AbstractMixed grass/legume pastures are an alternative to grass monocultures for increased beef cattle production in tropical climates. The objective of this study was to evaluate the productivity of beef cattle grazing either a mixed pasture of Brachiaria brizantha cv. Marandu grass and Arachis pintoi (forage peanut) cv. Belomonte or a Marandu monoculture, under rotational stocking. Five trials were conducted over a period of nine years in north‐eastern Brazil where the sward structure (forage, grass and legume mass) and animal performance were compared for a mixed Marandu grass/forage peanut pasture, and a Marandu grass monoculture with 120 kg N ha−1 y−1. Stocking rate was adjusted to maintain forage allowance at 4% body weight/day. A block design was used with four replicates, and warm and cool seasons within each trial were considered, using repeated measurements over time. In the warm season, the forage mass in the mixed pastures was 17% greater than in the monoculture (p = .049), and the stocking rate, average daily gain and liveweight gain per ha were 16.4%, 20.0% and 28.7% greater (p = .004, p < .001 and p < .001 respectively). The average daily gain showed a positive linear relationship with the legume proportion in the sward (p < .001). The mixed forage peanut/Marandu pasture sustained significantly greater beef cattle production (789 kg ha−1 y−1) compared to the N‐fertilized grass monoculture (655 kg ha−1 y−1). Appropriately managed, mixed pastures of forage peanut/Brachiaria pastures are sustainable and have high potential for use in the humid tropics.

Legumes increase grassland productivity with no effect on nitrous oxide emissions

AimsGrasslands are important agricultural production systems, where ecosystem functioning is affected by land management practices. Grass-legume mixtures are commonly cultivated to increase grassland productivity while reducing the need for nitrogen (N) fertiliser. However, little is known about the effect of this increase in productivity on greenhouse gas (GHG) emissions in grass-legume mixtures. The aim of this study was to investigate interactions between the proportion of legumes in grass-legume mixtures and N-fertiliser addition on productivity and GHG emissions. We tested the hypotheses that an increase in the relative proportion of legumes would increase plant productivity and decrease GHG emissions, and the magnitude of these effects would be reduced by N-fertiliser addition.MethodsThis was tested in a controlled environment mesocosm experiment with one grass and one legume species grown in mixtures in different proportions, with or without N-fertiliser. The effects on N cycling processes were assessed by measurement of above- and below-ground biomass, shoot N uptake, soil physico-chemical properties and GHG emissions.ResultsAbove-ground productivity and shoot N uptake were greater in legume-grass mixtures compared to grass or legume monocultures, in fertilised and unfertilised soils. However, we found no effect of legume proportion on N2O emissions, total soil N or mineral-N in fertilised or unfertilised soils.ConclusionsThis study shows that the inclusion of legumes in grass-legume mixtures positively affected productivity, however N cycle were in the short-term unaffected and mainly affected by nitrogen fertilisation. Legumes can be used in grassland management strategies to mitigate climate change by reducing crop demand for N-fertilisers.

UJI DAYA KECAMBAH LEGUM DESMANTHUS DENGAN SKARIFIKASI AIR PANAS PADA LAMA PERENDAMAN BERBEDA

Native pasture of semi-arid region in West Timor, Indonesia was low for the legume proportion was less than 10% as compared to that of the grass. Introducing shrub legume like Desmanthus could enhance the pasture quality. The hard seedness, however, was the barrier for germination. The time span of soaking the seeds in boiling water was one of the simple methods of scarification. A study has been conducted to measure the germination of Desmanthus leptophyllus and virgatus soaked in 80 o C hot water at different soaking times. A completely randomised design with seven treatments and three replicates was utilised. The treatments were soaking the seeds for 0 (T 0 ), 15 (T 15 ), 30 (T 30 ), 45 (T 45 ), 60 (T 60 ), 75 (T 75 ) or 90 (T 90 ) seconds before planting. Variables measured were germination rate, imbibed viable seeds, hard seeds, abnormal seeds and dead seeds. Data were analysed with one-way analysis of variance (ANOVA) SPSS 2014; SPSS Statistics for Windows, Version 23.0, IBM Corp, Armonk, NY, USA. The differences due to treatments were tested with Duncan’s test at P < 0.05 level. The results showed that soaking the seeds in hot water for 60 to 90 seconds enhanced germination up to 39 and 58% for Desmanthus leptophyllus (P < 0.05). Soaking the seeds of Desmanthus virgatus seeds for 30 to 90 seconds enhanced the germination rate ranging in between 50 and 66% (P < 0.05). It can be concluded that soaking the Desmanthus seeds in 80 o C hot water was one of the simple scarification methods that can enhance the germination rate but the soaking time requires attention. Key words: Desmanthus, hot water, scarification

Feeding functional responses in a sexually size-dimorphic bird

How animals use food resources according to their relative availability is essential for our understanding and predictions of ecosystem interaction. Non-linear functions between use and availability are described with the feeding functional response, a key tool to describe such functions that is still poorly understood in some cases. For example, in species with a marked sexual size dimorphism it is not clear how such non-linear functions differ between males and females. Here, we used likelihood methods and model selection to model non-linear functions in legume use by male and female great bustards (Otis tarda) based on diet composition data from droppings. The great bustard shows the highest sexual size dimorphism among birds, and it has opportunistic and generalist foraging habits, with a strong selection for legumes. Simple functional-response models described the proportion of legumes in great bustard droppings as a non-linear function of legume availability. Functional response type II fitted to data better than type III in autumn and winter, whereas in spring, type III was the best-fitted model, describing a dietary switch of great bustards feeding on legumes. The best-fitted functional response included an effect of sex in the asymptote of the curve; the female diet included a higher proportion of legumes than the male diet, suggesting a possible effect of sexual size dimorphism. We concluded that great bustards behaved as opportunistic foragers, whose sexual size dimorphism might play a role in the functional response to legumes.

Binary mixtures of alfalfa and birdsfoot trefoil with tall fescue: Herbage traits associated with the improved growth performance of beef steers

AbstractHigh nitrogen (N) fertilizer costs and increased environmental stewardship have renewed interest in grass–legume pastures. This research compared herbage mass, nutritive value, steer growth performance and economics of binary mixtures of tall fescue (Schendonorus arundinaceus [Schreb.] Dumort, nom. Cons.) (TF) with alfalfa (ALF) (TF + ALF, Medicago sativa L.) and birdsfoot trefoil (BFT) (TF + BFT, Lotus corniculatus L.), to tall fescue with (TF + N) and without N fertilizer (TF–N). Pastures were established in Lewiston, Utah, USA, and rotationally stocked by Angus beef steers for 112 days in 2012 and 2013. Herbage samples were collected prior to each 7‐day stocking period and analyzed for mass and nutritive value. Steers were weighed each 28‐day rotation cycle and cumulative average daily gain (ADG) calculated. Steer performance differed (p = .05) among most treatments with ADG greatest for TF + BFT (0.73 kg/day) and TF + ALF (0.67 kg/day), followed by TF + N (0.61 kg/day) and the least for TF–N (0.40 kg/day). Multivariate analysis indicated that small inherent differences in herbage energy, fiber and digestibility were highly correlated with steer growth. Other variables associated with ADG included legume proportion and herbage mass. Fescue–legume mixtures had 29 to 33% legume proportion, and more (p = .05) favorable energy and fiber concentrations than grass monocultures. Whereas herbage mass was greatest (p = .05) for TF + N (2,956 kg/ha), followed closely by TF + BFT (2,741 kg/ha) and TF + ALF (2,623 kg/ha). Overall, TF + BFT and TF + ALF pastures had less herbage, but better nutritive value and increased steer growth performance compared to TF + N, without the added cost of fertilizer.

EVALUATION OF AGRO-AMELIORATIVE CONDITION OF THE MAIN TYPES OF SOILS OF RICE CROP ROTATION

Relevance of research. The most common irrigation regime for rise in the world is constant flooding.
 Soils of rice crop rotation undergo significant changes during the construction of rice irrigation systems, and during their operation. This leads to the formation of so-called "rice soils" that is the result of the transformation of full-profile soils, which were partially or completely disturbed when planning and building rice checks. Keeping the water layer in the field for 4-5 months leads to irreversible changes in the morphological, physical and chemical soil properties. Therefore, it is relevant to determine the indicators of the soil cover, taking into account the features of the soils of rice crop rotations, in order to prevent the development of degradation processes and increase the productivity of rice crop rotation.
 The purpose of the study is to determine the main indicators of soil cover of rice crop rotation and their testing on a rice irrigation system with an area of ​​190 hectares.
 Methods and methods of research. During the study the following methods were used: field method - to study the basic soil properties; laboratory one - to study of physical and chemical, ameliorative, agrochemical soil properties and chemical composition of irrigation, subsoil, drainage and waste water; mathematical and statistical, comparative and retrospective - to evaluate the study results of the basic soil fertility indices.
 The research was carried out in the area of a rice irrigation system with 8-field crop rotation, where the proportion of rice does not exceed 50%. Rice was grown in accordance with the technology of rice growing, taking into account environmental protection requirements. For the companion crops, commonly used cultivation technologies were used. The system has been operated in a project mode for 50 years. The soil cover of the investigated system is represented by dark chestnut alkalized (72.9 hectares), meadow solonetz(18.9 hectares) and meadow chestnut alkalized (75.8 hectare) soil types.
 Research results. On the basis of analysis of retrospective data of monitoring study of the main indicators of agro-amelioration status of soils under rice crop rotation, the indicators of soil condition for the main soil types of rice irrigation systems were determined: groundwater level, groundwater mineralization, content of light-soluble salts in arable layer, chlorine ions content in soil-water extract, toxic salt content, soil salt balance, humus content, the content of easily hydrolyzed nitrogen compounds, the density of upper humus layer, the content of air-dry aggregates, content of water-stable aggregates.
 Conclusions. The approbation of the developed soil condition indicators on the rice irrigation system of the Rice Institute of the National Academy of Agrarian Sciences was carried out, which enabled to identify the main problems and specify the ways to overcome them. In the areas with meadow chestnut alkalized and meadow solonetzsoil types, it is necessary to increase their drainage capacity, namely to repair drainage networks. In the whole area of the investigated rice irrigation system, it is necessary to increase the proportion of perennial legumes and fallow land in the crop rotation, to do soil slitting or other types of mechanical soil treatments to improve its structural and aggregate composition, in particular, the content of air-dry soil aggregates in size of 0.25-10,00 mm and water-stable soil aggregates larger than 25 mm.

Tracing back sheep diet composition feeding grass-legume mixtures using fecal δ13C

Stable isotopes can be an important research tool to track C and N in grazing experiments. This study tested different proportions of C4 grass and legume and the correlation between dietary δ13C with fecal δ13C. Forty lambs, male, with average body weight of 20.4 kg, were randomized in a complete block design and fed Tifton-85 (Cynodon spp.) and Alfalfa (Medicago sativa) hays, at different levels of substitution composing five treatments: 1) 100% Tifton-85 hay; 2) 75% Tifton-85 + 25% alfalfa hay; 3) 50% Tifton-85 + 50% alfalfa hay; 4) 75% alfalfa + 25% Tifton-85 hay; 5) 100% alfalfa hay. The trial lasted 27 days, consisting of 22 days for adaptation and 5 days for collection of orts, feed, and feces. Fecal samples were collected directly from the rectum, to avoid contamination. All samples were collected during the 5-d sampling period, being composited at the end. Feed and fecal samples were dried for 72 h in an oven (55ºC) and ground in a Willey mill to pass a 2-mm sieve, incubated for 288 h in situ to obtain the indigestibility. All collected samples were subjected to indigestible neutral detergent fiber (iNDF) and carbon stable isotope analysis. Dietary isotopic composition (δ13C) in the iNDF residue processing was −14.98, −18.22, −23.85, −25.99, and −30.64‰ for treatments 1–5, respectively. The δ13C of dietary samples iNDF treated was −17.41, −20.27, −26.06, −27.83, and −31.67‰, respectively for diets 1–5. Fecal δ13C for non-treated samples was −16.23, −20.79, −25.10, -28.8, and −32.31‰, and for iNDF-treated sample −16.65, −21.52, −26.25, 29.20, and −32.06‰, respectively, for diets 1–5. Fecal samples were more depleted than diet samples, and the iNDF changed the fecal δ13C. The models used to back calculate the diets predicted well the diets by fecal δ13C, and the best models had R2 of 0.98 using non-treated samples, with similar results found when using iNDF-treated samples (R2 = 0.97). There is a 13C discrimination between dietary and fecal samples, however, the proportion of C3 and C4 species in the diet can be accurately predicted based on fecal samples using δ13C. The use of iNDF treated samples did not improve the models, as well as the addition of digestibility and indigestibility in the models.

Forage nitrogen yield and soil nitrogen in artificial grasslands with varied Medicago seedling proportion

ABSTRACTThis study aimed to understand the effects of Medicago spp proportion on symbiotic and non-symbiotic nitrogen (N) utilization of plants, and subsequent forage production and soil N status in an artificial Leymus chinensis grassland. By a two-year field experiment conducted in semi-arid northern China, it was found that the corresponding biomass proportions of legume in swards were 0, 39, 63, 83 and 98% when legume seedling proportions at sowing were 0, 25, 50, 75 and 100%, respectively. Increased Medicago seedling proportion (from 25 to 100%) decreased legume N2 fixation capacity from 53 to 21%, as a consequence, this reduced total symbiotic N2 fixation and its contribution to forage production with Medicago seedling proportion increasing from 50 to 75% or more. However, as increased Medicago seedling proportion enhanced legume biomass and sward uptake to soil mineral N, higher legume stands still led to the greater biomass and N yield. The cultures with 50% seedling of legume had 4–13% greater soil N concentration than the cultures with 0, 25, 75 and 100% seedling of legume. We concluded that pure Medicago stands led to the greatest forage yield, while medium Medicago stands could lead to the greater symbiotic N fixation and soil N concentration.

Soil nutrient levels define herbage yield but not root biomass in a multispecies grass-legume ley

The response of above- and below-ground biomass to soil nutrient availability is crucial for estimating belowground carbon input and predicting changes in soil carbon storage. However, the response is far from clear at plant community level, especially for grassland systems. Using a long-term field experiment initiated 123 years ago with varying soil nutrient levels (deficient, sub-optimal, optimal and over-optimal) established by use of two nutrient sources (animal manure or mineral fertiliser), we examined the effects of soil nutrient level and source on herbage yield and composition, root biomass and root-to-shoot (R/S) ratio of an unfertilised multispecies grass-legume ley. Increased nutrient levels enhanced herbage yield, but did not affect root biomass. The R/S ratio decreased from deficient to sub-optimal level, but remained constant from optimal to over-optimal level. Nutrient source did not influence herbage yield, root biomass or R/S ratio, but the legume proportion increased in soils previously receiving mineral fertiliser. The R/S ratio decreased with herbage yield, but did not vary with herbage composition. We conclude that soil nutrient level and herbage yield rather than nutrient source and herbage composition determine biomass allocation between aboveground and belowground in temperate grassland leys.