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Articles 451 - 480 of 12511
Full-Text Articles in Entire DC Network
Hastening Hay Drying, J W. Thomas, T R. Johnson, M A. Wieghart, C M. Hansen, M B. Tesar, Z Helsel
Hastening Hay Drying, J W. Thomas, T R. Johnson, M A. Wieghart, C M. Hansen, M B. Tesar, Z Helsel
IGC Proceedings (1977-2023)
The objectives of these studies were to increase the drying rate of cut alfalfa (Medicago sativa) by treating with chemical solutions and to examine factors that influence drying. Time to dry and drying rate of cut alfalfa were studied under laboratory and field conditions. Treatment consisted of spraying the cut alfalfa with methyl esters of long-chain fatty acids, an emulsifier alone, or a combination of an emulsifier and a potassium carbonate solution. Alfalfa sprayed with solutions of each chemical under specified conditions increased drying rate and decreased drying time to 60% or 75 % dry matter (DM) or …
Alternative Treatment Systems To Increase The Drying Rates Of Green Forage Crops, W E. Klinner, O D. Hale
Alternative Treatment Systems To Increase The Drying Rates Of Green Forage Crops, W E. Klinner, O D. Hale
IGC Proceedings (1977-2023)
Forms of conditioning treatment are being developed that aim to minimize the barrier effect of the crop cuticle without sacrificing too much of the structural strength of the herbage. Effective surface abrasion and favorable windrow structure can be achieved with steel-spoked rotors, which are now beginning to be offered commercially. More recently, plastic brushes have been developed because the higher population density and yielding ability of the crop-engaging elements, plus the absence of metal components, appeared to offer additional advantages. Four different brush conditioner systems have been evaluated in the laboratory and in replicated field experiments. Tufted brushes using trilobar …
Effects Of Microwave Treatment On Drying And Respiration In Cut Alfalfa, S A. Seif, D A. Holt, V L. Lechtenberg, R J. Vetter
Effects Of Microwave Treatment On Drying And Respiration In Cut Alfalfa, S A. Seif, D A. Holt, V L. Lechtenberg, R J. Vetter
IGC Proceedings (1977-2023)
After forage crops are cut mechanically, they usually undergo some degree of natural drying before being stored or further processed. During early stages of drying, plant respiration continues. Treatments or management practices that hasten drying and reduce postharvest respiration are desirable, because they minimize quantity and quality losses. Our objective was to determine the effects of brief microwave treatment on subsequent natural drying rate and respiration of alfalfa (Medicago sativa L. ). Duplicate samples of field grown Apollo alfalfa were subjected to focused microwave energy (2,450 MHz) generated at 0.25, 0.50, or 1.0 kilowatt of power for 3, 6, …
Effect Of Formic Acid- Formaldehyde Treatments On The Nitrogenous Constituents In Annual Ryegrass Silage, M L. Fishman, F Mchan, D Burdick
Effect Of Formic Acid- Formaldehyde Treatments On The Nitrogenous Constituents In Annual Ryegrass Silage, M L. Fishman, F Mchan, D Burdick
IGC Proceedings (1977-2023)
Prevention of proteolysis during ensiling is important in preserving the nutritive value of silage. Hence, the mechanism by which silage protein is protected against degradation was studied in wilted annual ryegrass (Lolium multiflorium Lam.) silage pretreated with formic acid, formaldehyde, and a formic acid-formaldehyde mixture. Raw-wilted ryegrass, control ryegrass silage, and treated ryegrass silage were extracted and fractionated under conditions previously found to maximize yield of nitrogenous constituents and minimize proteolysis during the extraction of fresh grass. Extractions were by boric acid-borate buffer at pH 8.0 with and without detergent (1 % sodium dodecyl sulfate). Sodium metabisulfite, an antioxidant, was …
Addition Of Lactobacillus Sp. To Aid The Fermentation Of Alfalfa, Corn, Sorghum, And Wheat Forages, N J. Moon, L O. Ely
Addition Of Lactobacillus Sp. To Aid The Fermentation Of Alfalfa, Corn, Sorghum, And Wheat Forages, N J. Moon, L O. Ely
IGC Proceedings (1977-2023)
As preservation of forage by ensiling has increased, so has the use of additives to enhance acid fermentation. Many of the fermentation aids currently on the market contain microflora to insure a lactic acid fermentation. The objectives of this study were to characterize the basic patterns of fermentation in a variety of crops and to evaluate the effects of adding selected microflora to forages to enhance the fermentation. Four crops were ensiled in each of three seasons. Alfalfa was harvested at 20 %-40 % bloom, second cut; wheat was cut in the early dough stage; corn was cut in the …
Interrelationships Between Pattern Of Fermentation During Ensilage And Initial Crop Composition, J M. Wilkinson, P F. Chapman, R J. Wilkins, R F. Wilson
Interrelationships Between Pattern Of Fermentation During Ensilage And Initial Crop Composition, J M. Wilkinson, P F. Chapman, R J. Wilkins, R F. Wilson
IGC Proceedings (1977-2023)
Relationships between crop composition and silage composition were examined for 231 silages made at the Grassland Research Institute from 1968 to 1978 without additives. A test was made of the model of Weissbach et al. (1974) in which silage characteristics were related to the percentage of dry matter in the crop (OM) and the ratio of sugar (Z) to buffering capacity (PK). Although these factors accounted for significant variance, the percentage accounted for was low at 36 % for lactic acid (percentage of total acids), 26 % for Flieg's score, 22 % for ammonia N (percentage of total N), and …
Effect Of Delayed Sealing During Ensiling On Fermentation And Dry-Matter Loss, N Takano, Y Masaoka, T Manda
Effect Of Delayed Sealing During Ensiling On Fermentation And Dry-Matter Loss, N Takano, Y Masaoka, T Manda
IGC Proceedings (1977-2023)
Two experiments were carried out from 1976 to 1980 to ascertain the effect of delayed sealing of silo on fermentation, dry· matter (DM) loss, digestibility, and silage intake. The effect of delayed sealing (up to 72 hours) of grass and corn silage was tested in laboratory silos on fermentation quality with storage temperatures at 15°C and 30°C, moisture content from 49% to 85 % , water-soluble carbohydrate (WSC) content ranging from 11.1 % to 17.5%, and with and without an addition of 0.25% formic acid. In all cases, delayed sealing resulted in poor-quality silage with high pH values and low …
Improving Hay Quality By Ammoniation, K J. Moore, V L. Lechtenberg, K S. Hendrix, J M. Hertel
Improving Hay Quality By Ammoniation, K J. Moore, V L. Lechtenberg, K S. Hendrix, J M. Hertel
IGC Proceedings (1977-2023)
Experiments were conducted to determine the effect of hay ammoniation on hay consumption and weight gain by steers when the hay was fed unsupplemented and supplemented with energy and protein. Mature orchardgrass (Dacrylis glomerata L.) hay was baled in early June 1979 and treated with anhydrous ammonia at 30 g/kg of hay. Seven weeks after treatment the hay was uncovered and allowed to aerate for 3 days. It was then fed to weanling steer calves weighing approximately 225 kg each. Similar hay baled from the same field but not ammoniated was fed to separate groups of steers. Both the treated …
Evaluations Of Low-Quality Roughages And Fibrous Cereal Grains Treated With Various Chemicals, G C. Fahey Jr, L L. Berger, M I. Mora, P J. Van Der Aar
Evaluations Of Low-Quality Roughages And Fibrous Cereal Grains Treated With Various Chemicals, G C. Fahey Jr, L L. Berger, M I. Mora, P J. Van Der Aar
IGC Proceedings (1977-2023)
Large improvements in the feeding value of low-quality roughages have resulted from treatment of them with various chemicals. Chemical treatment of grains may also be a potentially useful practice. The research reported here was designed (1) to determine how Chelating Metal Caustic Swelling (CMCS), a nontoxic, alkaline, aqueous reagent, compares with sodium hydroxide (NaOH) in enhancing in-vitro cellulose digestion (IVCD) of cornstalks (CS) (Zea mays) and soybean residues (SBR) (G!),cine max.), and (2) to evaluate the effects of NaOH and CMCS treatments of fibrous grains using in-situ techniques. CMCS or 7.5% NaOH solutions were added to CS or SBR at …
Effect Of Solvent Treatments On Intake And Digestibility Of Corn Stover, D M. Schaefer, M R. Ladisch, C H. Noller, V L. Lechtenberg
Effect Of Solvent Treatments On Intake And Digestibility Of Corn Stover, D M. Schaefer, M R. Ladisch, C H. Noller, V L. Lechtenberg
IGC Proceedings (1977-2023)
Treatment of crop residues with low levels of sodium hydroxide has been shown to improve organic-matter digestibility and animal performance. One objective of these experiments was to evaluate the effects of three treatments -water, sodium hydroxide, and chelating metal cellulose-swelling solution-on solubilization of cell-wall components in corn (Zea m£rys) stover. The two latter treatments were balanced for level of sodium hydroxide application, which was .3 .2 % of stover dry matter. The second objective was to determine the effects of these treatments on in-vitro and in-vivo digestibility as well as on consumption of corn stover. Twelve growing ram lambs were …
Factors Causing Greater In-Vitro Than In-Vivo Digestibility Of Sodium Hydroxide - Treated Roughages, L L. Berger, T J. Klopfenstein, R A. Britton
Factors Causing Greater In-Vitro Than In-Vivo Digestibility Of Sodium Hydroxide - Treated Roughages, L L. Berger, T J. Klopfenstein, R A. Britton
IGC Proceedings (1977-2023)
Research on sodium hydroxide (NaOH) treatment oflow-quality roughages generally indicates that in-vivo digestion is lower than in-vitro digestion. The purpose of this research was to identify factors that may cause less of the potentially digestible fiber to be digested in vivo than in vitro. Corn (Zea mays) cobs were raised to 60% moisture and treated to contain 0%, 2.5%, 5.0%, 7.5 % , and 10.0% NaOH. Lambs were fed diets containing 80% cobs and 20% supplement, giving a complete mixed diet con· taining 0%, 2.0%, 4.0%, 6.0%, and 8.0% NaOH. Five abomasally cannulated lambs were assigned to a 5 x …
Relationship Between Silage Quality And 15 N-Nitrate Reduction During Ensilage, K Ataku, M Horiguchi, T Matsumoto
Relationship Between Silage Quality And 15 N-Nitrate Reduction During Ensilage, K Ataku, M Horiguchi, T Matsumoto
IGC Proceedings (1977-2023)
Nitrate in forage has been proven to occasionally poison ruminants. Our recent studies, however, have shown that a high concentration of nitrate inhibits butyric acid fermentation to the advantage of the silage quality. This work was undertaken to see the relationship between silage quality and the pattern of nitrate reduction during ensilage.
Exploring Regenerative Vegetable Systems On The Central Coast Of California, Una S. O'Connell
Exploring Regenerative Vegetable Systems On The Central Coast Of California, Una S. O'Connell
Master's Theses
As climate change and current agricultural practices place pressure on the long term sustainability and resilience of food production systems, there is growing interest in whether existing agricultural systems can adapt to maintain productivity while improving environmental outcomes.
This study evaluated the effects of regenerative versus standard organic vegetable production systems on yield, insect communities, and weed suppression across three field trials conducted on California's Central Coast. In addition, I collected baseline soil health data for all trials. Trials 1 and 2 were carried out at the Cal Poly San Luis Obispo Organic Farm using cabbage and broccoli as cash …
Effect Of Leaf Harvesting Frequency On Cassava Leaf Production And Tuber Yield Of Binulak, Lakan 1 (Upl Cv-2), And Sultan 6 (Nsic 2003 Cv-25), Fides Marciana Z. Tambalo, Rosa Buena A. Capuno, Hiyasmin Rose L. Benzon, Jayson F. Garcia, Lizette Sahar N. Arcillas, Rona Joy C. Tud
Effect Of Leaf Harvesting Frequency On Cassava Leaf Production And Tuber Yield Of Binulak, Lakan 1 (Upl Cv-2), And Sultan 6 (Nsic 2003 Cv-25), Fides Marciana Z. Tambalo, Rosa Buena A. Capuno, Hiyasmin Rose L. Benzon, Jayson F. Garcia, Lizette Sahar N. Arcillas, Rona Joy C. Tud
The Philippine Agricultural Scientist
Cassava (Manihot esculenta Crantz) is a vital staple crop in many developing countries, valued for its adaptability and dual-purpose use of roots and leaves. This study investigated the effects of leaf harvesting frequency on the leaf and tuber yields of 3 locally grown cassava varieties: Binulak, Lakan 1, and Sultan 6. The experiment followed a split plot in a Randomized Complete Block Design with 4 treatments varying in leaf harvesting frequency and initiation. Cassava leaves were harvested at 4, 6, 8, or 10 mo after planting (MAP), and tubers were harvested at 10 MAP. Results indicated that leaf yield …
In Vitro Assessment Of The Reproductive Biology Of Sweet Potato Weevil, Cylas Formicarius (Fabricius) (Coleoptera: Brentidae) Among Commonly Grown Sweet Potato Cultivars, Jerah Mystica Novenario, Flor A. Ceballo-Alcantara
In Vitro Assessment Of The Reproductive Biology Of Sweet Potato Weevil, Cylas Formicarius (Fabricius) (Coleoptera: Brentidae) Among Commonly Grown Sweet Potato Cultivars, Jerah Mystica Novenario, Flor A. Ceballo-Alcantara
The Philippine Agricultural Scientist
The sweet potato weevil, Cylas formicarius (Fabricius), is a devastating pest of sweet potato, Ipomoea batatas (L.) Lam., with a specific point of damage at the tuber where eggs are oviposited, and voracious larvae feed. Farmers in Tarlac province in the Philippines claim that a specific cultivar is highly infested by the pest, suggesting that other cultivars may not be susceptible to the pest damage. This study aimed to determine the reproductive biology of the weevil across 3 sweet potato cultivars (Inubi, Super Bureau, and Bureau) frequently grown in Central Luzon. Since the weevils are nocturnal, behavioral observations were conducted …
Marker-Assisted Identification Of Hybrids In Polyembryonic ‘Carabao’ Mango (Mangifera Indica L.) Breeding In The Philippines, John Edward L. Felipe, Kyla Andrea G. Mendoza, Benjamin Christian J. Esguerra, Carolyn E. Alcasid, Gino R. Hernandez, Eureka Teresa M. Ocampo
Marker-Assisted Identification Of Hybrids In Polyembryonic ‘Carabao’ Mango (Mangifera Indica L.) Breeding In The Philippines, John Edward L. Felipe, Kyla Andrea G. Mendoza, Benjamin Christian J. Esguerra, Carolyn E. Alcasid, Gino R. Hernandez, Eureka Teresa M. Ocampo
The Philippine Agricultural Scientist
Varietal improvement of the Philippine ‘Carabao’ mango (Mangifera indica L.) through conventional breeding is constrained by polyembryony, which makes it difficult to distinguish zygotic hybrids from nucellar seedlings at early developmental stages. This study evaluated the utility of simple sequence repeat (SSR) markers for early and accurate identification of hybrids in polyembryonic ‘Carabao’ mango crosses. Genomic DNA was isolated from 24 parental accessions and 61 putative hybrid seedlings using a modified CTAB protocol that yielded DNA suitable for PCR-based marker analysis. Eighty-one SSR markers were screened across 29 parental combinations, of which 64 markers (79.0%) were polymorphic in at …
Postharvest Response Of Jute Mallow (Corchorus Olitorius L.) Tops To Different Storage Temperatures, Wella L. Absulio-Morales, James L. Tababa, Daphne Cassandra H. Gonzales, Genesis M. Banawa, Angelo C. Castro, Arlan James D. Rodeo
Postharvest Response Of Jute Mallow (Corchorus Olitorius L.) Tops To Different Storage Temperatures, Wella L. Absulio-Morales, James L. Tababa, Daphne Cassandra H. Gonzales, Genesis M. Banawa, Angelo C. Castro, Arlan James D. Rodeo
The Philippine Agricultural Scientist
Jute mallow (Corchorus olitorius L.), locally known as saluyot, is a nutrient-rich leafy vegetable, but its potential remains underutilized due to its high perishability. This study determined the postharvest behavior of jute tops stored at 4 different temperatures (5, 13, 20, and 28 °C). Key quality parameters were measured at specific time intervals. The marketable shelf life of jute tops was 7 d at 5 and 13 °C, but only 2 and 3 d at 28 and 20 °C, respectively. This shorter shelf life was mainly due to wilting caused by high weight loss, especially at higher temperatures. …
Can Generative Ai Make Farming Decisions? Current Status And Future Pathways: A Case Study In Row Crop Production With Chatgpt, Nipuna Chamara, Yufeng Ge, Joe Luck, Yu Pan, Saleh Taghvaeian, Cory Walters, Christopher Proctor, Daran Rudnick, Daren Redfearn
Can Generative Ai Make Farming Decisions? Current Status And Future Pathways: A Case Study In Row Crop Production With Chatgpt, Nipuna Chamara, Yufeng Ge, Joe Luck, Yu Pan, Saleh Taghvaeian, Cory Walters, Christopher Proctor, Daran Rudnick, Daren Redfearn
Department of Agricultural and Biological Systems Engineering: Faculty Publications
The agricultural decision-making process is experience-based, knowledge-dependent, time-sensitive, complex, and driven by historical data. Planting, fertilization, irrigation, and chemigation are key categories in farm decision-making, and currently there is no one-shot decision-support tool that covers all these activities. Generative Artificial Intelligence (AI) models are more advanced than traditional machine learning and deep learning models. These models have been trained on vast amounts of data from the internet, allowing them to accept unstructured data in various forms and generate human-like text, solutions to problems, and scenario predictions. Given this capability, we became interested in exploring the potential of generative AI in …
Fate Of Nitrogen Applied To Grassland In Animal Wastes, M Sherwood
Fate Of Nitrogen Applied To Grassland In Animal Wastes, M Sherwood
IGC Proceedings (1977-2023)
The experiment was designed to determine the effects of land spreading of animal manures on the nutrient content of surface runoff water and infiltrating soil water. This report deals only with nitrogen (N) and attempts to quantify the losses through runoff, leaching, and volatilization of ammonia (NH3) as well as N uptake in the grass over a 3-year period. Experimental plots sited on grassland, on two soil types (a moderately drained loam and an impermeable gley), were equipped to collect surface runoff water. Ceramic probes were installed in each plot at 15-, 30-, 60-, and 100-cm depths to extract infiltrating …
Annual Losses Of Ammonia From A Grazed Pasture Fertilized With Urea, V R. Catchpoole, L A. Harper, R J.K Keyers
Annual Losses Of Ammonia From A Grazed Pasture Fertilized With Urea, V R. Catchpoole, L A. Harper, R J.K Keyers
IGC Proceedings (1977-2023)
Nitrogen-balance studies have shown losses of applied nitrogen (N) from grazed pastures in southeastern Queensland. Losses as high as 80% have been observed from urea N broadcast at 376 kg N/ha/yr over 8 years on a Setaria sp1uu:elata cv. Nandi pasture. Management techniques aimed at reducing this loss and thereby increasing the efficiency of use of N by pastures cannot be devised until the pathways of loss are known. The objective of this research was to estimate the annual ammonia (NH3) loss by convective transport from a urea-fertilized pasture at Samford Pasture Research Station in southeastern Queensland. Urea was broadcast …
Nitrogen Losses From Urine-Affected Areas Of A New Zealand Pasture, Under Contrasting Seasonal Conditions, P R. Ball, D R. Keeney
Nitrogen Losses From Urine-Affected Areas Of A New Zealand Pasture, Under Contrasting Seasonal Conditions, P R. Ball, D R. Keeney
IGC Proceedings (1977-2023)
Grazing ruminants aggregate large quantities of forage nitrogen (N) into urine patches. Pasture plots treated with urine N were studied to assess its fate under contrasting seasonal conditions: cool-moist (representing winter-spring); warm-moist (late spring-early summer), and warm-dry (late summer-autumn). A permanent ryegrass (Lolium perenne L.)-white clover (Trifolium repens L.) sward on free-draining alluvial soil was studied. 'freatments were replicated in randomized blocks. Urine N was applied at 30 or 60 g N/m2• Relevant measurements were then continued until treatment differences disappeared. Apparent N balances for urine treatments were compiled. Fixation by white clover was always greatly reduced in …
Effects Of Grazing Management On Seasonal Variation In Nitrogen Fixation, J L. Brock, J H. Hoglund, R H. Fletcher
Effects Of Grazing Management On Seasonal Variation In Nitrogen Fixation, J L. Brock, J H. Hoglund, R H. Fletcher
IGC Proceedings (1977-2023)
Using the acetylene reduction assay, field studies in recent years have investigated the variation in N fixation in grazed systems, and some of the principles involved in the interaction with available soil N have been described. This experiment extends this work to include the effect of grazing management on the factors influencing N fixation. Two self-contained sheep-grazed units, one a 10-paddock rotationally grazed system and the other set stocked, were established on a high-fertility ryegrass-white clover pasture, with a basic stocking rate of 22 sheep/ha. Over the 1975-1978 period, both units were monitored for pasture growth, N fixation, and associated …
Symbiotic Nitrogen Fixation Of Alfalfa, Birdsfoot Trefoil, And Red Clover, G H. Heichel, C P. Vance, D K. Barnes
Symbiotic Nitrogen Fixation Of Alfalfa, Birdsfoot Trefoil, And Red Clover, G H. Heichel, C P. Vance, D K. Barnes
IGC Proceedings (1977-2023)
Forage legumes such as alfalfa (Medicago sativa L.), birdsfoot trefoil (Lotus comiculatus L.), and red clover (Trifolium pratense L.), grown in crop rotations, can provide an inexpensive source of nitrogen (N) to succeeding crops. Few quantitative measurements of seasonal patterns of N fixation in managed communities of perennial forage legumes have been undertaken, chiefly because of the lack of satisfactory methods. Therefore, there is little knowledge of how N fixation varies with crop development, yielding ability, and weather patterns. Quantitative measurements of N fixation are important in choosing the appropriate legume for use in a crop rotation and for …
Photosynthate Supply And Nitrogen Fixation In Forage Legumes, P M. Murphy
Photosynthate Supply And Nitrogen Fixation In Forage Legumes, P M. Murphy
IGC Proceedings (1977-2023)
Photosynthate supply is known to limit nitrogen fixation in legumes, and the resulting shortfall in energy supply necessary for maximum crop production may be aggravated by the energy-wasteful process of hydrogen (H2) evolution by the legume N2 fixing system. There is less information available on these aspects of the nitrogen-fixing process in forage legumes, such as white clover (Trifolium repens). The objectives of the present work were to determine how N2(C2H2) fixation and H2 production are influenced by carbohydrate supply in forage legumes.
Plants were grown under controlled environmental conditions, and nodule energy supply was varied by adjusting …
Selection Of Rhizobium Strains For Enhanced Dinitrogen Fixation In Forage Legume Production, C Hagedorn, W E. Knight
Selection Of Rhizobium Strains For Enhanced Dinitrogen Fixation In Forage Legume Production, C Hagedorn, W E. Knight
IGC Proceedings (1977-2023)
A set of procedures for the selection of Rhizobium strains for enhanced dinitrogen fixation in forage legumes is presented. Although forage legumes are among the most efficient members of the Leguminosae regarding biological nitrogen fixation (BNF), they are generally neither productive nor persistent without effective nodulation by appropriate rhizobia. The following methods define a selection and evaluation process to obtain appropriate Rhizobium strains. These include (1) regional survey of the production area, (2) strain collection and soil analyses, (3) strain characterization, (4) strain selection and manipulation, and (5) field evaluation of strains. The initial procedure is to survey the region …
Interactions Between Grasses And Rhizosphere Nitrogen-Fixing Bacteria, M H. Gaskins, D H. Hubbell, S L. Albrecht
Interactions Between Grasses And Rhizosphere Nitrogen-Fixing Bacteria, M H. Gaskins, D H. Hubbell, S L. Albrecht
IGC Proceedings (1977-2023)
Sorghum and Digitaria cultivars grown in soil or nutrient solutions were inoculated with a strain of Azospirillum in short-term greenhouse experiments. Carbon compounds lost by roots in solution culture experiments were determined in order to estimate the quantity of energy substrates that might be obtained by rhizosphere organisms from growing plants. Other plants were treated with plant growth hormones, and responses were compared to those of plants treated with killed Azospirillum cells. The similarity of the responses suggests that growth-hormone production by the inoculant organism, rather than nitrogen (N) fixation, is responsible for part or all of the increase in …
Simple Computer Simulation Models For Forage-Management Applications, G W. Fick, D Onstad
Simple Computer Simulation Models For Forage-Management Applications, G W. Fick, D Onstad
IGC Proceedings (1977-2023)
Dynamic computer simulation models of forage growth can be useful in interpreting physical and biological limitations on production and in designing management systems for testing in the field. The explanatory detail of such models makes them both more reliable and more expensive to use than simple empirical formulations. Simple simulation models reduce the expense. They can also serve as reference points for designing, evaluating, or selecting more complex versions and thus provide a more rational basis for using models in grassland research and management. Our objectives were to develop and to test a simple dynamic simulation model of alfalfa (Medicago …
Energy Flow And Conversion Efficiency In Grazing Grassland, T Akiyama, S Takahashi, M Shiyomi, T Okubo
Energy Flow And Conversion Efficiency In Grazing Grassland, T Akiyama, S Takahashi, M Shiyomi, T Okubo
IGC Proceedings (1977-2023)
Measurable energy storage on grassland ecosystems was examined for 5 years at the Fujinita site under the same rotation program with two grazing intensities. Daily global solar radiation and photosynthetic active radiation were measured as the energy sources in the ecosystem. Primary production by pasture plants and amount grazed by cattle were estimated by the biomass differences inside and outside of protection cages. For the estimation of energy produced or stored by plants or cattle, calorific values were examined for dominant plant species at the Fujinita site. Seasonal changes in digestibility were investigated to ascertain the energy of herbage digested …
A System Approach To Swedish Ley Production, J F. Angus, A Kornher, B.W R. Torssell
A System Approach To Swedish Ley Production, J F. Angus, A Kornher, B.W R. Torssell
IGC Proceedings (1977-2023)
A simulation model for estimating yield of leys from standard meteorological observations is described. It is based on an S-shaped growth curve also accounting for phasic development and regrowth depression. Effects of temperature, radiation, and soil moisture are accounted for by a growth index. Soil moisture is simulated with a standard water budget. The parameters in the model were estimated by comparing measured with calculated growth. The model then predicted final harvest with reasonable accuracy, but with underestimate of early season growth, presumably due to mobilization of carbohydrate from storage organs. Observed ley yields from 49 Swedish parishes (1961-1978) were …
Age, Date Of Cutting, And Temperature As Factor Affecting Chemical Composition Of Berseem (Trifolium Alexandrinum L.), F Guessous
IGC Proceedings (1977-2023)
Chemical composition ofberseem (Trifolium alexandrinumL.), produced in winter and spring under irrigation in Morocco, was investigated in a 4-year study. Berseem was planted at various dates, and after the first cut had been harvested, samples were taken from each regrowth at weekly intervals. Total plant samples and leaf and stem samples were analyzed for dry matter
(DM), ash, crude protein (CP), and crude fiber (CF). A total of 172 samples of above-ground regrowth were analyzed and used to calculate multiple regressions of chemical composition on age and date of cutting. Date of cutting was defined as number of …