Agricultural Science Commons^™

2022 Western Australian Crop Sowing Guide, B. Shackley, B. Paynter, J. Bucat, M. Seymour, S. Power

Bulletins 4000 -

Welcome to the 2022 edition of the Crop Sowing Guide for WA, which introduces 27 new variety releases: three wheat, nine barley (three recently accredited for malt and six currently under malt evaluation), twelve canola, two field pea and a lentil.

The Crop Sowing Guide for WA has been compiled by officers in the Department of Primary Industries and Regional Development. It provides information to support variety decisions for each of the major crops for the upcoming season.

In this edition, lupin agzones have been reduced from 8 agzones to 6 so that all varieties for each of the major …

Identification And Validation Of High Ld Hotspot Genomic Regions Harboring Stem Rust Resistant Genes On 1b, 2a (Sr38), And 7b Chromosomes In Wheat, Shamseldeen Eltaher, Amira M.I. Mourad, P Stephen Baenziger, Stephen Wegulo, Vikas Belamkar, Ahmed Sallam

Department of Agronomy and Horticulture: Faculty Publications

Stem rust caused by Puccinia graminis f. sp. tritici Eriks. is an important disease of common wheat globally. The production and cultivation of genetically resistant cultivars are one of the most successful and environmentally friendly ways to protect wheat against fungal pathogens. Seedling screening and genome-wide association study (GWAS) were used to determine the genetic diversity of wheat genotypes obtained on stem rust resistance loci. At the seedling stage, the reaction of the common stem rust race QFCSC in Nebraska was measured in a set of 212 genotypes from F3:6 lines. The results indicated that 184 genotypes (86.8%) had different …

Long-Term Maize-Desmodium Intercropping Shifts Structure And Composition Of Soil Microbiome With Stronger Impact On Fungal Communities, Aneth David Mwakilili, Kilaza Samson Mwaikono, Sebastian Larsson Herrera, Charles A.O. Midega, Francis Magingo, Beatrix Alsanius, Teun Dekker, Sylvester Leonard Lyantagaye

All Peer-Reviewed Publications

Purpose: Push–pull is an intercropping technology that is rapidly spreading among smallholder farmers in Sub-Saharan Africa. The technology intercrops cereals with Desmodium to fight off stem borers, eliminate parasitic weeds, and improve soil fertility and yields of cereals. The above-ground components of push–pull cropping have been well investigated. However, the impact of the technology on the soil microbiome and the subsequent role of the microbiome on diverse ecosystem benefits are unknown. Here we describe the soil microbiome associated with maize—Desmodium intercropping in push–pull farming in comparison to long-term maize monoculture. Methods: Soil samples were collected from long-term maize—Desmodium intercropping and …

Response Of Mixed C4 Grasses To Various Multiple Paddock Grazing Strategies, B. E. Anderson, W. H. Schacht

IGC Proceedings (1977-2023)

The botanical composition of mixed grass pastures may change during grazing due to the various grazing period/recovery period lengths associated with multiple-paddock grazing strategies. This 4-year study compared changes in relative species composition and basal plant cover of a C₄ grass mixture grazed using a nested paddock design to simulate 2, 4, 6 and 12- paddock grazing cells in eastern Nebraska. Total basal plant cover declined from 11.6% prior to grazing to 7.3% after one year of grazing and then remained nearly constant thereafter. Neither relative species composition nor basal density were affected greatly by grazing strategy. Within grazing …

Spatial And Time Distribution Of Dairy Cattle Manure In An Intensive Pasture System, S. L. White, S. P. Washburn, L. D. King, R. E. Sheffield, J. T. Green Jr.

IGC Proceedings (1977-2023)

This study determined distribution of feces and urine from dairy cattle managed in a rotationally grazed pasture. Lactating Holsteins (n=18) and Jerseys (n=18) were grazed on a .74 ha endophyte-free fescue (Festuca arundinacea)/white clover (Trifolium repens) pasture. All cows were constantly observed for 24 h 6 times over 12 mo. Cows had access to about 54% of the paddock during the first grazing period (12 h) and had access to the entire paddock during the second grazing period (8 h). Data included: (1) all feces and urine events from eight cows, observed while in the pasture, …

Test Of A Conversion Equation To Increase The Accuracy Of Microhistological Analysis Of Herbivore Diets In The Pantanal, S. A. Santos, C. Costa, A. Pott, J. M. Alvarez

IGC Proceedings (1977-2023)

Forty forage species samples were collected in September 1999, including grass, sedges, forbs, shrubs and trees. Seven hand-compounded mixtures of known botanical composition and dry weight were prepared. Five slides of each mixture were made and 20 frequency observations were recorded per slide. Two procedures were used to determine percent composition on a dry weight basis and their values were converted to correct the proportion of the unidentifiable fragments amongst species. Estimated and actual values differed significantly (P < 0.05) in 31.7%, 34.1%, 12.2% and 12.2% of the species for frequency addition (FA), density convertion (DC), frequency addition converted (FAC) and density convertion converted (DCC), respectively. The average similarity values between estimated and observed mixture were 90.2, 86.0, 94.2 and 93.3 for FA, DC, FAC and DCC, respectively. In conclusion, food habits by microscopic analysis may be described using any of the procedures tested because they rank important forage species for herbivores.

Effects Of Herbage Allowance Upon Animal Performance And Grazing Behavior Of Strip-Grazed Heifers, Claudio F. Machado, F. Di Croce, F. Gonzalez, H. Zeballos, N. J. Auza, M. H. Wade, S. T. Morris, J. Hodgson

IGC Proceedings (1977-2023)

A trial was designed to test the effect of herbage allowance (HA) on live-weight gain (LWG) and grazing behavior of heifers during spring as part of a combined field-modeling research programme. Low HA (L) and high HA (H) of 2.5 and 5.0 kg DM herbage mass 100 kg animal LW^-1day^-1 were fed respectively. H animals grazed longer and achieved a higher LWG than L (P < 0.05). H animals left a higher residual pasture (P < 0.051) with a significantly (P < 0.05) higher content of green, clover, non-lamina and petiole of a higher digestibility and NSC, with a lower NDF content. The significance of some factors involved in these results on intake and diet selection are discussed in relation to the predictability of animal performance.

Rapid Quantitative Analysis Of Toxic Norditerpenoid Alkaloids In Larkspur (Delphinium Spp.) By Flow Injection - Electrospray Ionization – Mass Spectrometry, Dale R. Gardner, Stephen T. Lee, Daniel Cook

Poisonous Plant Research (PPR)

A rapid flow injection - electrospray ionization – mass spectrometry (FI-ESI-MS) method for the quantitative and qualitative analysis of norditerpenoid alkaloids in larkspur plants was developed. The FI-ESI-MS method was calibrated for alkaloid concentrations with larkspur plant samples against an existing Fourier transform infrared spectroscopy FTIR method. There was a strong correlation (r = 0.9926, r = 0.9891) between the FTIR and FI-ESI-MS methods. The relative standard deviation (RSD) for all measurements were ≤ 6.2 % except for the sample with the lowest concentration which was 19%. The sample throughput of the FI-ESI-MS method is much higher than the FTIR …

Spatial Frameworks For Robust Estimation Of Yield Gaps, Juan I. Rattalino Edreira, José F. Andrade, Kenneth G. Cassman, Martin K. Ittersum, Marloes P. Van Loon, Patricio Grassini

Department of Agronomy and Horticulture: Faculty Publications

Food security interventions and policies need reliable estimates of crop production and the scope to enhance production on existing cropland. Here we assess the performance of two widely used ‘top-down’ gridded frameworks (Global Agro-ecological Zones and Agricultural Model Intercomparison and Improvement Project) versus an alternative ‘bottom-up’ approach (Global Yield Gap Atlas). The Global Yield Gap Atlas estimates extra production potential locally for a number of sites representing major breadbaskets and then upscales the results to larger spatial scales. We find that estimates from top-down frameworks are alarmingly unlikely, with estimated potential production being lower than current farm production at some …

Factors Influencing The Yield Proportions Of Plantago Lanceolata L. And Taraxacum Officinale Web. In Lolium Perenne L. Swards, Harald Laser

IGC Proceedings (1977-2023)

Diaspores of Plantago lanceolata and Taraxacum officinale respectively were sown in established Lolium perenne swards to determine the dynamics of their yield proportions during five years. The experimental factors were forb species, variety of the grass species (= early or late flowering), N-fertilization, and sward density. The amount of nitrogen fertilizer had the most important effect on yield proportions of the forb species and also on the total dry-matter (= DM) yield. The single creation of gaps in grass swards before sowing forbs had a lasting positive effect on the Plantago lanceolata and Taraxacum officinale proportions. Peak proportions of Taraxacum …

Dynamic Of Native Pasture Influenced By Deferment Of Grazing And Fertilization, K. E. Gomes, G. E. Maraschin, J. Riboldi

IGC Proceedings (1977-2023)

Native pastures of southern Brazil cover 12 million ha and are the main forage feed resource for most domestic livestock. However, their heavy and continuous use has reduced standing biomass and the presence of good forage species, reducing animal performance and jeopardizing the ecosystem sustainability. An alternative for better use of these pastures and their preservation is grazing deferment that allow natural reseeding. The objective of this research was evaluate native pasture dynamic after six years of grazing deferments (GD) periods and soil fertilization effects by point-quadrat method every season. All pasture components were affected by GD, with prostrate grasses …

Evaluation Of Plant Functional Types Response To Grazing And Fertilizer Levels In Natural Grassland, Zélia M. S. Castilhos, V. D. Pillar

IGC Proceedings (1977-2023)

We report a study on a natural grassland experiment with the objective of finding optimal plant functional types (PFTs) for the description of vegetation response to levels of grazing (ungrazed, grazed) and fertilizer (with, without). The experiment was a split-plot design in randomized blocks, with three replications and the grazing levels in the main plots. Vegetation description was based on species composition and on 12 plant morphology attributes (life-form, growth-form, stem tissue type, leaf cross section, leaf texture, leaf dorsal epidermal surface, leaf ventral epidermal surface, spininess, leaf resistance, leaf width, plant height). Cover-abundance of species was visually estimated. By …

Mountain Pastures Structure And Its Relationship With Grazing, I. Albizu, S. Mendarte, G. Besga, I. Amezaga, M. Onaindia

IGC Proceedings (1977-2023)

The present work aims toward an approach to mountain pastures as a system of relationships in which it is needed to point out those environmental factors that reflect more clearly their structure and potential productivity. This initial step of pasture tipification is important as a previous activity before the planning and management of protected areas because these areas support an intensive pastoral activity. In order to achieve this objective a field study was conducted in two areas in the Gorbeia Natural Park (Bizkaia): Arraba and Aldamiñape, located at 900-1100 masl. In each pasture four plots were selected according to orientation …

Structure And Function Vegetation Conditions By Grazing Processes In A Humid Pampean Grassland (Argentina), O. E. Ansín, Estrella M. Oyhamburu, E. A. Hoffmann, M. A. Eirin

IGC Proceedings (1977-2023)

Expressed changes were evaluated as consequence of the cattle grazing, or their exclusion, in the structure of plant communities of the Flooding Pampa. We center our interest in the species numbers, plant cover, species diversity and forage availability. The treatments were: a) continuous grazing, b) enclosure grazing and c) controlled grazing. The enclosure grazing area was installed two years before starting the measurements. In the continuous grazing St. Augustine grass (Stenotaphrum secundatum Walt.) holds its initial cover of 64 % and dallis grass (Paspalum dilatatum Poir.) the 15 %. In the enclosure grazing S. secundatum decreased its cover …

Nitrogen Dynamics From Decomposing Litter Of Panicum Maximum With Different Nitrogen And Phosphorus Content In Brazilian Alfissol, R. M. Schunke, J. C. Kiehl, Valdinei T. Paulino, S. Urquiaga, R. M. Bodey, B. Alves

IGC Proceedings (1977-2023)

The objective of this study was to measure the dynamics (immobilization and release) of N and to evaluate the effect of the initial chemical composition of four Panicum maximum cultivars grown in a Alfisol and fertilized with different levels of nitrogen (0, 80 e 160 kg ha^-1 de N) and phosphorus (0 e 200 kg ha^-1), on the release of the N from the litter using the litterbags technique. There was an increase in the litter initial concentration of N with time of decomposition. The Aruana and Vencedor cultivars released about 70 and 60% of N; respectively, …

Impact Of Grazing Management Strategies On Carbon Sequestration In A Semi-Arid Rangeland, Usa, J. D. Reeder, G. E. Schuman, J. A. Morgan, D. R. Lecain, R. H. Hart

IGC Proceedings (1977-2023)

The effects of 12 years of grazing management strategies on carbon (C) distribution and sequestration were assessed on a semi-arid mixed-grass prairie in Wyoming, USA. Five grazing treatments were evaluated: non-grazed exclosures; continuous, season-long grazing at a light (22 steer-days ha^-1) stocking rate; and, rotationally-deferred, short-duration rotation, and continuous, season-long grazing, all three at a heavy stocking rate (59 steer-days ha^-1). Non-grazed exclosures exhibited a large buildup of dead plant material (72% of total aboveground plant matter) and forb biomass represented a large component (35%) of the plant community. Stocking rate, but not grazing strategy, changed …

Contribution Of Dairy Cow Manure To Soil Fertility And Nutrient Redistribution In Pastures, S. R. Aarons, C. R. O'Connor, M. Hall, C. J. P. Gourley

IGC Proceedings (1977-2023)

The effects of dairy cow manure on soil fertility were investigated at the site of the long-term phosphorus rate by stocking rate farmlet experiment at the Dairy Research Institute, Ellinbank, in Victoria. Manure increased extractable soil P (Olsen) in the 0 - 5 cm layer after 60 days to 61 mg/kg compared with values of 32 mg/kg in the control soils. Extractable soil K (Colwell) almost doubled under manure pads to 5 cm depth from 642 mg/kg in control soils to 1226 mg/kg in manure treated soils. The effects of grazing management on nutrient redistribution and pasture growth within strip-grazed …

Impact Of Increasing Nitrogen Fertilizer Rates Upon An Irrigated Tanzania Grass Pasture. 1. Dry Matter Yield, F. Queiroz-Neto, G. B. Martha Jr., M. A. Penati, M. Corsi, M. J. T. Menezes

IGC Proceedings (1977-2023)

An experiment was carried out with irrigated Tanzania grass (Panicum maximum, Jacq.) pasture receiving five nitrogen (N) rates of (0, 30, 60, 90 and 120 kg N ha-¹ cut-¹) during the growing season. N application increased dry matter yield and Tanzania growth rate linearly (P < 0.05). Responses to nitrogen applications were higher in the first two cuts of the growing season than in the last two cuts. The N fertilizer conversion into herbage dry matter was also higher in the beginning of the growing season.

Short-Term Study On 13Carbon Discrimination On Irrigated Tropical Pasture, G. B. Martha Jr., M. Corsi, P. C. O. Trivelin, F. Queiroz-Neto

IGC Proceedings (1977-2023)

A better understanding of pasture ecosystem can be obtained through the use of ¹³C discrimination technique. In this context, an experiment, assigned in a randomized complete block design with four replicates, was conducted to evaluate the Δ ¹³C (‰) discrimination, nitrogen (N) yield (kg N ha-¹), total nitrogen content (g kg dry matter (DM)-¹) and dry matter yield (kg DM ha-¹) on an irrigated Tanzania grass pasture (Panicum maximum, Jacq.) receiving increasing rates (0, 30, 60, 90 and 120 kg N ha-¹ cut-¹) of N fertilizer during the summer. Dry matter yield, N yield and nitrogen …

Apparent Recovery Of Surface Applied Nitrogen Fertilizer By A Coastcross Pasture, A. C. Primavesi, O. Primavesi, L. A. Corrêa, H. Cantarella, A. G. Silva

IGC Proceedings (1977-2023)

Nitrogen recoveries from five levels of urea and ammonium nitrate surface-applied on coastcross pasture, grown on a dark red latosol (Hapludox), in São Carlos, SP, Brazil, under tropical altitude climate, were estimated. Significant differences occurred within periods (P < 0.05), depending on climatic conditions. Under adequate plant growth conditions, mean N recovery from urea was about 67%, sometimes reaching 80%, of that from ammonium nitrate. Recovery of ammonium nitrate varied from 45 to 68% of applied N.