scholarly journals Legumes increase grassland productivity with no effect on nitrous oxide emissions

2019 ◽  
Vol 446 (1-2) ◽  
pp. 163-177 ◽  
Author(s):  
Arlete S. Barneze ◽  
Jeanette Whitaker ◽  
Niall P. McNamara ◽  
Nicholas J. Ostle

Abstract Aims Grasslands 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. Methods This 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. Results Above-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. Conclusions This 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.

1993 ◽  
Vol 28 (3-5) ◽  
pp. 691-700 ◽  
Author(s):  
J. P. Craig ◽  
R. R. Weil

In December, 1987, the states in the Chesapeake Bay region, along with the federal government, signed an agreement which called for a 40% reduction in nitrogen and phosphorus loadings to the Bay by the year 2000. To accomplish this goal, major reductions in nutrient loadings associated with agricultural management practices were deemed necessary. The objective of this study was to determine if reducing fertilizer inputs to the NT system would result in a reduction in nitrogen contamination of groundwater. In this study, groundwater, soil, and percolate samples were collected from two cropping systems. The first system was a conventional no-till (NT) grain production system with a two-year rotation of corn/winter wheat/double crop soybean. The second system, denoted low-input sustainable agriculture (LISA), produced the same crops using a winter legume and relay-cropped soybeans into standing wheat to reduce nitrogen and herbicide inputs. Nitrate-nitrogen concentrations in groundwater were significantly lower under the LISA system. Over 80% of the NT groundwater samples had NO3-N concentrations greater than 10 mgl-1, compared to only 4% for the LISA cropping system. Significantly lower soil mineral N to a depth of 180 cm was also observed. The NT soil had nearly twice as much mineral N present in the 90-180 cm portion than the LISA cropping system.


Atmosphere ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 563
Author(s):  
Kelsey Anderson ◽  
Philip A. Moore ◽  
Jerry Martin ◽  
Amanda J. Ashworth

Gaseous emissions from poultry litter causes production problems for producers as well as the environment, by contributing to climate change and reducing air quality. Novel methods of reducing ammonia (NH3) and greenhouse gas (GHG) emissions in poultry facilities are needed. As such, our research evaluated GHG emissions over a 42 d period. Three separate flocks of 1000 broilers were used for this study. The first flock was used only to produce litter needed for the experiment. The second and third flocks were allocated to 20 pens in a randomized block design with four replicated of five treatments. The management practices studied included an unamended control; a conventional practice of incorporating aluminum sulfate (referred to as alum) at 98 kg/100 m2); a novel litter amendment made from alum mud, bauxite, and sulfuric acid (alum mud litter amendment, AMLA) applied at different rates (49 and 98 kg/100 m2) and methods (surface applied or incorporated). Nitrous oxide emissions were low for all treatments in flocks 2 and 3 (0.40 and 0.37 mg m2 hr−1, respectively). The formation of caked litter (due to excessive moisture) during day 35 and 42 caused high variability in CH4 and CO2 emissions. Alum mud litter amendment and alum did not significantly affect GHGs emissions from litter, regardless of the amendment rate or application method. In fact, litter amendments such as alum and AMLA typically lower GHG emissions from poultry facilities by reducing ventilation requirements to maintain air quality in cooler months due to lower NH3 levels, resulting in less propane use and concomitant reductions in CO2 emissions.


2017 ◽  
Vol 6 (2) ◽  
pp. 66 ◽  
Author(s):  
Maria Storrle ◽  
Hans-Jorg Brauckmann ◽  
Gabriele Broll

This study investigates the amounts of greenhouse gas (GHG) emissions due to manure handling within different livestock production systems in Tyumen oblast of Western Siberia. Tyumen oblast occupies approx. 160 000 km² of Asian taiga and forest steppe. The amount of GHGs from manure was calculated as a function of the handling according to current IPCC guidelines for ecozones and livestock production systems. The entire Tyumen oblast has annual 7 400 t methane emissions and 440 t nitrous oxide emissions from manure. Three livestock production systems are prevalent in Tyumen oblast: Mega farms, small farms and peasant farms. The share of mega farms is 81 % (171 kt CO2 eq). Additionally, the slurry system in mega farms causes environmental pollution. GHG emissions and environmental pollution could be reduced by implementing solid manure systems or pasturing, by installing storage facilities for slurry outside the stables and through application of the manure as fertiliser at mega farms. In small farms solid manure systems and a small stocking density of livestock lead to smallest GHG emissions (1 %, 3 kt CO2 eq) from manure. In peasant farming 18 % (38 kt CO2 eq) of GHGs are emitted due to pasturing. 


2013 ◽  
Vol 10 (3) ◽  
pp. 1787-1797 ◽  
Author(s):  
M. H. Jeuffroy ◽  
E. Baranger ◽  
B. Carrouée ◽  
E. de Chezelles ◽  
M. Gosme ◽  
...  

Abstract. Approximately 65% of anthropogenic emissions of N2O, a potent greenhouse gas (GHG), originate from soils at a global scale, and particularly after N fertilisation of the main crops in Europe. Thanks to their capacity to fix atmospheric N2 through biological fixation, legumes can reduce N fertilizer use, and possibly N2O emissions. Nevertheless, the decomposition of crop organic matter during the crop cycle and residue decomposition, and possibly the N fixation process itself, could lead to N2O emissions. The objective of this study was to quantify N2O emissions from a dry pea crop (Pisum sativum, harvested at maturity) and from the subsequent crops in comparison with N2O emissions from wheat and oilseed rape crops, fertilized or not, in various rotations. A field experiment was conducted over 4 consecutive years to compare the emissions during the pea crop, in comparison with those during the wheat (fertilized or not) or oilseed rape crops, and after the pea crop, in comparison with other preceding crops. N2O fluxes were measured using static chambers. In spite of low N2O fluxes, mainly due to the site's soil characteristics, fluxes during the crop were significantly lower for pea and unfertilized wheat than for fertilized wheat and oilseed rape. The effect of the preceding crop was not significant, while soil mineral N at harvest was higher after the pea crop. These results should be confirmed over a wider range of soil types. Nevertheless, they demonstrate the absence of N2O emissions linked to the symbiotic N fixation process, and allow us to estimate the decrease in N2O emissions by 20–25% through including one pea crop in a three-year rotation. On a larger scale, this reduction of GHG emissions at field level has to be added to the decrease due to the reduced production and transport of the N fertilizer not applied to the pea crop.


Soil Research ◽  
2004 ◽  
Vol 42 (7) ◽  
pp. 737 ◽  
Author(s):  
D. Curtin ◽  
F. M. McCallum

Nitrogen (N) mineralised from soil organic matter can be an important source of N for crop uptake, particularly following cultivation of pastures. Difficulty in predicting the contribution of mineralisation continues to be a serious obstacle to implementating best management practices for fertiliser N. We evaluated biological tests (i.e. net N mineralised in a 28-day aerobic incubation and anaerobically mineralisable N, AMN) and chemical tests (ammonium-N hydrolysis in hot 2 m KCl) as predictors of N supply to a glasshouse-grown oat (Avena sativa L.) crop. The oat plants were grown to maturity without added N on 30 soils representing a range of management histories, including soils collected from long-term pastures and intensive arable cropping sites. The majority (average 83%) of the N accumulated in grain and straw was mineralised N. Plant N derived from mineralisation (PNDM), estimated by subtracting soil mineral N at sowing from N uptake, was generally higher for long-term pasture soils (mean 82 mg/kg, n = 9) than for long-term arable soils (mean 48 mg/kg, n = 9). The 2 measures of N mineralisation were not closely related [R2 = 0.11 (0.37*** when one outlying observation was omitted)], indicating that aerobic and anaerobic assays can give quite different N fertility rankings. Aerobically mineralisable N was the best predictor of PNDM (R2 = 0.79***). The ratio of CO2-C evolved to net N mineralised in the aerobic incubation was highly variable (e.g. mean of 13.6 for pasture soils v. 7.5 for long-term arable soils), likely due to differences in N immobilisation. The correlations of AMN (R2 = 0.32**) and hot KCl N (R2 = 0.24**) with PNDM were not much better than that between total soil N and PNDM (R2 = 0.16*), suggesting that these tests would not provide reliable estimates of N mineralisation potential in soils with diverse management histories.


2014 ◽  
Vol 76 ◽  
pp. 211-216
Author(s):  
Iris Vogeler ◽  
Mark Shepherd ◽  
Gina Lucci

Abstract Dairy farms are under pressure to increase productivity while reducing environmental impacts. Effective fertiliser management practices are critical to achieve this. We investigated the effects of N fertiliser management on pasture production and modelled N losses, either via direct leaching of fertiliser N, or indirectly through N uptake and subsequent excretion via dairy cow grazing. The Agricultural Production Systems Simulator (APSIM) was first tested with experimental data from fertiliser response experiments conducted on a well-drained soil in the Waikato region of New Zealand. The model was then used in a 20- year simulation to investigate the effect of fertiliser management on pasture response and the impacts on potential leaching losses. The risk of direct leaching from applied fertiliser was generally low, but at an annual rate of 220 kg N/ha exceeded that from urine patches in one out of 10 years. The main effect of N fertiliser on leaching risk was indirect via the urine patch by providing higher pasture yields and N concentrations. Best management practices could include identification of high risk periods based on environmental conditions (e.g. soil moisture, plant growth), avoidance of fertiliser applications in these periods and the use of duration controlled grazing (DCG) to prevent excreta deposition onto the grazing area during critical times. Keywords: Modelling, APSIM, N fertilisation rates, N fertilisation timing, direct and indirect leaching, urine patches


Author(s):  
Guillaume Martin ◽  
Roger Martin-Clouaire ◽  
Jean-Pierre Rellier ◽  
Michel Duru

Fulfilling the production objectives of a grassland-based beef system requires a robust management strategy to secure the best practicable use of forage resources with regard to the cattle demand. To address the challenging issue of designing such strategies, this article describes the application of an ontology of agricultural production systems to the generic conceptual model SEDIVER, which supports the representation and dynamic farm-scale simulation of specific grassland-based beef systems. The most salient and novel aspects of SEDIVER concern the explicit modeling of (a) the diversity in plant, grassland, animal and farmland, and (b) management strategies that deal with the planning and coordination of activities whereby the farmer controls the biophysical processes. By using the SEDIVER conceptual framework, part of the subjective and context-specific knowledge used in farm management can be captured and, in this way, enable scientific investigation of management practices.


Soil Systems ◽  
2019 ◽  
Vol 3 (4) ◽  
pp. 76
Author(s):  
Xia Zhu-Barker ◽  
Mark Easter ◽  
Amy Swan ◽  
Mary Carlson ◽  
Lucas Thompson ◽  
...  

Greenhouse gas (GHG) emissions from arid irrigated agricultural soil in California have been predicted to represent 8% of the state’s total GHG emissions. Although specialty crops compose the majority of the state’s crops in both economic value and land area, the portion of GHG emissions contributed by them is still highly uncertain. Current and emerging soil management practices affect the mitigation of those emissions. Herein, we review the scientific literature on the impact of soil management practices in California specialty crop systems on GHG nitrous oxide emissions. As such studies from most major specialty crop systems in California are limited, we focus on two annual and two perennial crops with the most data from the state: tomato, lettuce, wine grapes and almond. Nitrous oxide emission factors were developed and compared to Intergovernmental Panel on Climate Change (IPCC) emission factors, and state-wide emissions for these four crops were calculated for specific soil management practices. Dependent on crop systems and specific management practices, the emission factors developed in this study were either higher, lower or comparable to IPCC emission factors. Uncertainties caused by low gas sampling frequency in these studies were identified and discussed. These uncertainties can be remediated by robust and standardized estimates of nitrous oxide emissions from changes in soil management practices in California specialty crop systems. Promising practices to reduce nitrous oxide emissions and meet crop production goals, pertinent gaps in knowledge on this topic and limitations of this approach are discussed.


2021 ◽  
Vol 61 (1) ◽  
pp. 92
Author(s):  
Belay Duguma

Context Evaluation of the performance of dairy cows kept in different production systems is essential for the development of appropriate breeding strategies. Aims To examine milk production and reproductive performance of crossbred (CB) and indigenous (I) dairy cows, farmers’ traits preference for CB and I breeding females, and factors affecting the performance of dairy cattle on smallholdings in selected towns of Jimma Zone, Ethiopia. Methods In total, 52 smallholder dairy cattle farmers were randomly sampled and data were collected through individual face-to-face interviews by using structured questionnaires. The traits studied were daily milk yield (DMY), lactation milk yield (LMY), lactation length (LL), age at first service (AFS), age at first calving (AFC), calving interval (CI), days open (DO), and number of service per conception (NSC), all being factors affecting performance of dairy cattle and farmers’ preferred dairy traits. Results On average, CB cows had significantly (P < 0.05) higher DMY (6.0 ± 0.33 vs 1.8 ± 0.07 L/cow), LMY (1466.7 ± 1.13 vs 376.0 ± 21.02 L (L)), LL (8.1 ± 0.41 vs 6.9 ± 0.22 months), and lower AFS (2.69 ± 0.1 vs 3.3 ± 0.07 years), AFC (3.7 ± 0.13 vs 4.3 ± 0.07 years) and CI (21.2 ± 1.37 vs 29.8 ± 1.30 months) than did I cows. However, DO and NSC were not significantly (P > 0.05) affected by genotype. In order of perceived importance, high milk yield (mean rank = 0.306), LL (0.292) and fertility (0.199) were farmers’ most preferred traits for CB breeding cows, and the corresponding preferred traits for I cows were high milk yield (0.253), adaptability (0.229) and LL (0.192). The most important factors perceived by farmers affecting the performance of dairy cattle were breed, nutrition, diseases, breeding and management practices Conclusions The findings of the study indicated that even though CB cows performed better, the performance of both breeds of dairy cows in the study area was found to be generally low due to delayed AFS, late AFC, long CI, shorter LL, low daily and LMY and high NSC. Implications The study highlighted that there is a potential for increasing the performance of dairy cows in the study area, through improved management strategies leading to shorter AFS, AFC, CI and lower NSC. Furthermore, future breed-improvement programs should take into consideration farmers’ trait preferences in design of sustainable improvement programs.


2021 ◽  
Vol 23 (3) ◽  
pp. 279-285
Author(s):  
NISHANT K SINHA ◽  
M. MOHANTY ◽  
J. SOMASUNDARAM ◽  
R. S. CHAUDHARY ◽  
H. PATRA ◽  
...  

The evaluation of climatic change impact on maize grain and biomass yield under different N management practices through a well-calibrated and validated APSIM model in Vertisol of central India has been made. Climate scenarios were derived from seven global climate models (GCM) for two representative concentration pathways (RCPs), i.e. RCP4.5 and RCP8.5, and two-time slices, i.e. 2050 and 2080. The five N scenarios, namely N0%, N50%, N100%, N150%, and 100% organic, were studied in different climatic scenarios. The probability of exceedance showed that N0%, N50%, N100%, N150%, and 100% organic treatments have a 50% chance of yield greater than 1.0, 3.40, 4.20, 4.45 and 3.84 t ha-1, respectively. The average reduction of maize yield was -44.4, -20, -19.7 - 17.9 and 22.5 per cent in N 0%, N 50%, N 100%, N 150%, 100% organic, respectively under RCP4.5 over the baseline period (1980-2010). For RCP8.5, the average reduction of maize yield in N 0%, N 50%, N 100%, N 150%, 100% organic was 41.2, 21.2, 20.8 20.6 and 23.1 per cent, respectively. Simulation results suggested that a higher decrease of maize yield in 100 per cent organic treatments than inorganic treatments is due to variability in N uptake.


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