Agricultural Science Commons^™

The Use Of Digestate As Fertilizer: Effect On Cocksfoot Productivity And Total Energy Input, Vita Tilvikienė, Žydrė Kadžiulienė, Zenonas Dabkevičius

IGC Proceedings (1977-2023)

The financial viability of bioenergy production is mostly influenced by the productivity and quality of the biomass (Lehtomäki et al. 2011; Šiaudinis et al. 2012. Biogas which is an important form of bioenergy, is composed of methane and carbon dioxide produced from the anaerobic digestion of organic raw materials. To maximize the economic value of the anaerobic digestion process, both biogas and digestate should be efficiently utilized.

The energy input for grass grown specifically for biogas production ranges from 4.1 to 24.5 GJ/ha (Kryževičienė et al. 2005; Navickas et al. 2006; Navickas et al. 2011) …

Carbon And Nitrogen Stocks In Integrated Crop Livestock, Valdinei T. Paulino, Erika M. L. C. Teixeira, Marcos Siqueira Neto

IGC Proceedings (1977-2023)

Soil organic matter (SOM) is recognized as an important characteristic of sustainable agricultural systems in the tropics and temperate regions. It is considered an integrated characteristic of physical, chemical and biological soil conditions and has been used as a soil quality index in different land uses and management practices (Lal 2011). Environmental, social, and financial imbalances have occurred, requiring producers to become more efficient. A system of intercropping grain crops with forages can provide enough forage in the dry season to maintain nutritional quality of livestock and even promote weight gain (Castro Filho et al. 1991). An integrated crop-livestock system …

The Mineral Nutrients Content And The Organic Manure Quality Appraisal For The Stylosanthes Green Manure, Guo-Dao Liu, Dong-Fen Huang, Xi Wen, Chang-Jun Bai, Dao-Geng Yu, Heng-Fu Huan

IGC Proceedings (1977-2023)

Stylo (Stylosanthes spp.) is a leguminous crop planted widely in the world tropics. In the past the stylo was commonly used as pasture with high quality, and was less used as a green manure. However, stylo is recently used more as a green manure in tropical plantations. As there is little relevant research on the organic manure quality for stylo, the purpose of this research was to evaluate the quality of stylo green manure. Selection of stylo green manure with the highest quality was based on the analysis of nutrients and organic matter content in stylo.

Influence Of Stocking Rate, Grazing Season Length And Dairy Cow Genetic Strain On The Nitrogen Balance Of Grass Based Dairy Production Systems, Deirdre Hennessy, Willie Ryan, Laurence Shalloo

IGC Proceedings (1977-2023)

Stocking rate (SR), grazing season (GS) length and Holstein-Friesian (HF) strain can have a profound effect on the productivity of grass-based milk production systems. The optimum SR is that which gives the maximum sustainable economic output of product per unit area. Increasing SR increases output per ha, but also requires increased inputs of feed and fertilizer. Increasing the proportion of grazed grass utilized for milk production improves the economic sustainability of the system (Dillon et al. 2008). Nitrogen (N) use efficiency is one of the key drivers of environmentally and economically sustainable agricultural production systems. Achieving the optimum balance …

Urinary Recovery Of Dicyandiamide (Dcd) Pulse-Dosed Into The Rumen Of Non-Lactating Dairy Cows, And The Effects Of Applying Urine With Dcd To Lysimeters On Nitrous Oxide And Nitrate Leaching In Ireland, Patrick J. O’Connor, Eva Lewis, Helen Slattery, Deirdre Hennessy

IGC Proceedings (1977-2023)

Urine excreted by dairy cows is a source of nitrogen (N) to the sward. The N content of urine is high, up to 1000 kg N/ha and is usually in excess of sward requirements. Surplus N is usually lost through a number of pathways including nitrate (NO₃^-) leaching and nitrous oxide (N2O) emissions. Dicyandiamide (DCD), a nitrification inhibitor, has been shown to reduce NO₃^- leaching and N₂O emissions when applied as a fine particle suspension (FPS) to grazed paddocks. The objectives of the study were to: (1) quantify the recovery of DCD in …

Improving The Phosphorus Efficiency Of Temperate Australian Pastures, Richard J. Simpson, Graeme A. Sandral, Richard A. Culvenor, Megan H. Ryan, Hans Lambers, Phillip G. H. Nichols, Richard C. Hayes

IGC Proceedings (1977-2023)

Phosphorus (P) is a key input necessary for high production in many temperate, grass-legume pasture systems in Australia because the pastures are situated on P-deficient and moderate to highly P-sorbing soils. A consequence of P-sorption in these soils is that much more P must be applied as fertiliser than will be exported in animal products. The P balance efficiency (PBE=100*P_export/Pi_nputs) of grazing enterprises (e.g. wool, meat, milk and live animal export) is about 10-30% and compares poorly with some other agricultural enterprises (e.g. 45-54% for grain production; McLaughlin et al. 1992; Weaver and …

Leaching Of Nitrate From A Grassland Field, Abdulfatah F. Aboufayed

IGC Proceedings (1977-2023)

Agricultural activities are the major cause of non-point pollution. Mechanization of agriculture, artificial fertilizer use and overall intensification of farming has played a major role in the increased incidence of pollution by agricultural activities. Carton et al. (2006) reported the effects of agricultural practices on nitrate leaching from an intensively managed dairy farm and showed that mean concentrations of nitrate nitrogen in the groundwater beneath the farm during the two monitoring years exceeded the maximum admissible concentration (MAC) for drinking water. While average nitrate nitrogen concentration in soil water were less than MAC, there was a trend for increased nitrogen …

Soil Phosphate Solubilising Bacteria Of The Okavango Floodplains, Botswana, Tabo Mubyana-John, Lawrence Tarupiwa, Wellington R. L. Masamba, Susan Ringrose

IGC Proceedings (1977-2023)

Phosphorus although abundant is among the most limiting macro plant nutrients in some soils. Deficiencies are often seen as purpling of leaves due to unavailability of PO₄ in soil solution. In soil solution PO₄ solubility is pH dependent; at pH < 6, it is often bound to Fe or Al, while at pH > 7 it forms insoluble complexes with Ca, Mg, K or Na making it unavailable to plants (Brady 2002). Soil organic P requires mineralisation then solubilisation by the enzyme phosphatase before being available. Botswana soils due to the low rainfall (< 450 mm/yr) are characterised by high pH and salt pans scattered all over the semi-arid and arid landscape. Cultivation of most of these soils often results in P deficient crops (Leuschner and Manthe 1996). However, in grassland areas of the Okavango, very few grasses show P deficiency. Studies from other areas indicate that some grasses habour PO₄ solubilizing bacteria in their rhizosphere that help them in their P sequencing quest (Duponnois et al. …

Should Native Pastures Be Fertilised?, Jo I. Powells, Doug J. Alcock, Luke C. Pope, Denys Garden

IGC Proceedings (1977-2023)

Considerable research has been conducted in recent years demonstrating the ongoing benefits of phosphorus (P) fertiliser in achieving and maintaining higher levels of production from native pastures (Graham 2006; Garden et al. 2003; Lodge et al. 2003; Michalk et al. 2003). However Garden et al. (2003), Hill et al. (2004) and Dorrough et al. (2008) all question the sustainability of this practice by highlighting changes in species composition of these pastures with regard to increasing the introduced annual grass and broadleaf weed components at the expense of the native grasses and forbs but in …

Humic Products–Potential Or Presumption For Agriculture. Do Humic Products Have A Place In Australian Grazing Enterprises?, Kim L. Billingham

IGC Proceedings (1977-2023)

Australian soils are inherently low in organic matter. Agricultural practices have compounded this problem. As farmers look for more sustainable farming methods a commercial niche has opened for a range of alternative products including the humic products. More than 200 humic products are manufactured and sold by Australian companies (Billingham 2012). Many more can be purchased via overseas websites.

The term ‘humic products’ denotes a range of materials derived from lignites (brown coals), peats, lignins, composts and other organic wastes. Most are manufactured by alkali and acid extraction of the source material. Humic products are usually sold as soil amendments …

Efficient Use Of Phosphorus In Temperate Grassland Systems, Richard J. Simpson, Alan E. Richardson, Shirley N. Nichols, James R. Crush

IGC Proceedings (1977-2023)

Phosphorus (P) fertilisers are important for high production in many grassland systems. However, there are increasing environmental, economic and strategic issues associated with using P, which is a non-renewable and “effectively finite” global resource. We review the P balance of temperate pastures to identify the factors that contribute to inefficient P use and discuss ways to improve P use efficiency. The most immediate gains can be made by ensuring that pastures are not over-fertilised. Plants with low critical P requirements, particularly as a result of better root foraging, will be important. Root traits such as fine roots (root diameter), branching, …

Nitrogen Management In Grasslands And Forage-Based Production Systems–Role Of Biological Nitrification Inhibition (Bni), Guntur V. Subbarao, Idupulapati M. Rao, K. Nakahara, Y. Ando, K. L. Sahrawat, T. Tesfamariam, J. C. Lata, S. Boudsocq, J. W. Miles, Manabu Ishitani, M. Peters

IGC Proceedings (1977-2023)

Nitrogen (N), being the most critical and essential nutrient for plant growth, largely determines the productivity in both extensive- and intensive- grassland systems. Nitrification and denitrification processes in the soil are the primary drivers generating reactive-N: NO₃^-, N₂O, and NO, and is largely responsible for N-loss and degradation of grasslands. Suppressing nitrification can thus facilitate the retention of soil-N to sustain long-term productivity of grasslands and forage-based production systems. Certain plants can suppress soil nitrification by releasing inhibitors from roots, a phenomenon termed ‘biological nitrification inhibition’ (BNI). Recent methodological developments (e.g. bioluminescence assay …

Assessment Of Drought Resistance For 17 Alfalfa Varieties At The Seedling Stage, Lin Meng, Peichun Mao, Qiang Guo

IGC Proceedings (1977-2023)

Alfalfa is a crop of relative water demand, and the good quality, the high and stable yield could be obtained directly depending on water supplies and strong or weak drought resistance ability of alfalfa cultivars (Geng 1995; Chen and Jia 2000). To guide steady and effectively development of alfalfa industrialization in the arid and semi-arid regions of China, we systematically selected the excellent drought resistant alfalfa cultivars, and then identified and assessed their drought resistant capacity. In this study, a pot experiment was conducted by simulating drought stress in a greenhouse to assess the drought resistance of seventeen alfalfa cultivars …

Effect Of Forage Brassica On Subsequent Soil Water Content And Yield Of Dual-Purpose Winter Wheat In Rainfed Region Of Northwestern China, Yuanbo Liu, Lihua Tian, Qingping Zhang, Yuying Shen

IGC Proceedings (1977-2023)

The dual-purpose performance of winter wheat used for both forage and grain production has been explored as an alternative practice for filling the feed gap during winter and spring in agricultural areas of the Loess Plateau. Profit-ability is still restricted however, because of a three month summer fallow period between harvest and planting of the subsequent wheat crop. During this 3 month period 60% of the annual precipitation occurs, limiting the effective use of soil water and compounding the risk of soil erosion. Thus it is important to cultivate some forage crops with higher water consumption, protecting the ecological environment …

Using Forages To Conserve Water In Semi-Arid Irrigated Cropping Systems, Rick Kellison, V. G. Allen, C. P. Brown, D. L. Doerfert, P. N. Johnson, S. J. Maas, C. P. West

IGC Proceedings (1977-2023)

The Texas High Plains are part of the largest, contiguously irrigated cropland in the USA, and draws water from the Ogallala aquifer. High crop prices, increased demand for maize for ethanol production, and severe drought have increased water depletion rates. Research has shown that integrating forages and grazing cattle into the cotton-dominant cropping system can reduce overall water use (Allen et al. 2012) while still offering farmers positive net returns (Johnson et al. 2013). Integrating forages with row crops also reduces needs for nitrogen (N) fertilizer, rebuilds soil organic matter (Acosta-Martinez et al. 2010), and reduces fossil energy …

Flexible Forage Systems For Variable Water Supplies, Mary-Jane E. Rogers, Alister Lawson, Kevin Kelly

IGC Proceedings (1977-2023)

The dairy industry in northern Victoria, Australia is primarily based on the border check irrigation of temperate forage species over the spring to autumn period. Traditionally, dairy cows have grazed the perennial species (white clover and perennial ryegrass) and annual pastures (based on short-lived ryegrasses and subterranean or Persian clover). However, due to a more variable climate – particularly a period where the annual rainfall has been significantly less than the long-term average – the summer irrigation allocations have been substantially lower and more variable than the preceding 20-30 years. Under this climate scenario, dairy farmers are re-evaluating their feed …

Delayed Sowing Decreased Lucerne Dry Matter Yield Over Two Seasons, Richard Sim, Derrick Moot

IGC Proceedings (1977-2023)

Lucerne (Medicago sativa L.) can be sown in New Zealand from late spring (October) to early autumn (March). In the establishment season, greatest drymatter (DM) yields are normally attained from sowing early and production lost from delayed sowing is only considered in the establishment season. The objective of this research is to determine if sowing date continues to have an effect on DM yield in year two and how the partitioning of DM between the above and below ground plant fractions is influenced by sowing date.

Dynamic Simulation And Definition Of Crop Coefficient For Typical Steppe In Inner Mongolia, China, Hou Qiong

IGC Proceedings (1977-2023)

There are few reference values for crop coefficients for natural grassland in FAO Irrigation and Drainage papers. The aim of this paper was to define crop coefficients under different water conditions for typical steppe vegeation in Inner Mongolia, based on actual observation data and statistical analysis, so as to accurately calculate the water demand and actual evapotranspiration of plant community in Inner Mongolia.

The North Wyke Farm Platform: Methodologies Used In The Remote Sensing Of The Quantity And Quality Of Drainage Water, Bruce A. Griffith, Jane M. B. Hawkins, Robert J. Orr, Martin S. A. Blackwell, Phil J. Murray

IGC Proceedings (1977-2023)

The North Wyke Farm Platform(NWFP) for agri-environmental research in temperate grassland was established in the UK in 2010 (Orr et al. 2011). Here we describe the instrumentation and methodologies used to monitor the quantity and quality of drainage water at a total of 15 H-flumes draining 5 sub-catchments within three farmlets. Each of 15 flume laboratories is supplied with 3 kW of mains power and connected to both fibre optic and UHF (Ultra High Frequency) radio networks for data exchange. The radio data network also provides telemetry for rain gauges and soil temperature/moisture probes located away from the flumes …

Managing Water Resources In Australian Temperate Pastures, David Mitchell

IGC Proceedings (1977-2023)

Increasing the amount of perennial vegetation changes the water balance at both farm and catchment scale. At the farm scale, changes to the flows of water and salt are generally as expected, though some perverse outcomes may occur, such as a shortage of surface water for stock. From a catchment perspective, downstream users are little affected by decreases in streamflow volumes, river flows appear to be more typical of pristine flows, and upstream landholders benefit from improved resilience.