Mass to height relationships in annual pastures and prediction of sheep growth rates

2014 ◽  
Vol 54 (9) ◽  
pp. 1305
Author(s):  
S. M. Robertson
Keyword(s):  
Feed Intake ◽  
Dry Matter ◽  
Dry Matter Accumulation ◽  
Sheep Grazing ◽  
Software Model ◽  
Low Mass ◽  
Grazing Systems ◽  
Sheep Production ◽  
Relationship Of ◽  
The Relationship

The relationship between pasture height and mass influences the availability of pasture for grazing, and is important for predicting intake of pasture and liveweight change by sheep. The relationship between pasture mass and structure and sheep production is poorly defined for low-mass, clumpy pastures in low-rainfall regions. Between 2001 and 2004, 480 quadrats of pastures were measured in 23 paddocks throughout the Victorian Mallee. Pasture height was related to live mass for medic (linear; r2 = 0.70; P < 0.001) and grassy medic (asymptotic; r2 = 0.64; P < 0.001) pastures, and prediction of grassy medic pasture height was improved by inclusion of proportion live groundcover. During 2004, pasture dry matter accumulation and liveweight changes in sheep grazing annual pastures were measured and compared with predicted outputs from GrazFeed, a software model used to estimate feed intake and liveweight change in sheep. Improved predictions of liveweight gain in grazing sheep were obtained using measured height rather than the GrazFeed default height. The results show that the height to mass relationship of annual pastures in the Victorian Mallee differs between pasture types, between years, and may differ from other published relationships. This study provides information that may assist in the development of models of grazing systems.

Prediction of the voluntary intake of grass silages by beef cattle. 1. Linear regression analyses

1990 ◽  
Vol 50 (3) ◽  
pp. 425-438 ◽  
Author(s):  
A. J. Rook ◽  
M. Gill
Keyword(s):  
Dry Matter ◽  
Volatile Fatty Acids ◽  
Live Weight ◽  
Ammonia Nitrogen ◽  
Dry Matter Intake ◽  
Digestible Organic Matter ◽  
Voluntary Intake ◽  
Relationship Of ◽  
The Relationship ◽  
Linear Regressions

ABSTRACTData on individually recorded silage dry-matter intake (SDMI), concentrate dry-matter intake (CDMI) and live weight of steers and data on silage composition including toluene dry matter (TDM), pH, total nitrogen (N), ammonia nitrogen (NH3-N), volatile fatty acids (VFAs), digestible organic matter in the dry matter (DOMD) and neutral-detergent fibre (NDF) obtained from experiments conducted at three sites were used to obtain simple and multiple linear regressions of SDMI on other variables.Live weight accounted for a high proportion of the variation in intake but this effect could generally be removed by scaling intake by live weight raised to the power of 0·75 (M0·75). CDMI was the most important factor affecting scaled intake in mixed diets. TDM, NH,-N and VFAs all had important effects on SDMI. The relationship of SDMI with TDM was curvilinear suggesting that there is little to be gained in intake terms from wilting to TDM above 250 g/kg. The effect of NH3-N appeared to be related more to its correlation with VFAs than with any other nitrogenous constituent while the VFAs appeared to have a direct effect on SDMI. The effects of N and pH on SDMI were generally small. DOMD and NDF had relatively little effect on SDMI. Significant differences in intercepts between sites were found for most relationships although common slopes were often found.

Common Sunflower (Helianthus annuus) Interference in Soybean (Glycine max)

1996 ◽  
Vol 10 (2) ◽  
pp. 317-321 ◽  
Author(s):  
Patrick W. Geier ◽  
Larry D. Maddux ◽  
Loren J. Moshier ◽  
Phillip W. Stahlman
Keyword(s):  
Dry Matter ◽  
Market Price ◽  
Yield Reduction ◽  
Soybean Yield ◽  
Sunflower Plant ◽  
Matter Production ◽  
Competition Study ◽  
Soybean Canopy ◽  
Relationship Of ◽  
The Relationship

An in-row competition study was conducted in 1991 and 1992 near Silver Lake, KS to determine the relationship of noncultivated common sunflower density to soybean yield, PAR at the soybean canopy, and common sunflower dry matter production. Because of environmental differences, year main effect interactions occurred, so results are presented by year. For example, 0.3 common sunflower plant/m2produced 4030 kg/ha of aboveground dry matter in 1991 and 1300 kg/ha in 1992. Soybean yield reduction ranged from 19 and 17% with 0.3 common sunflower plant/m2to 97 and 95% with 4.6 plant/m2, in 1991 and 1992, respectively. Assuming a treatment cost of $35/ha and a soybean market price of $0.21/kg, economic threshold levels were 0.1 common sunflower plant/m2in 1991, and 0.07 in 1992. Common sunflower at 0.3 plant/m2reduced PAR at the soybean canopy by 390 and 300 μE/m2/s, or 24 and 18% in 1991 and 1992, respectively. We conclude that the ability of common sunflower to intercept PAR above the soybean canopy is an important component in its interference with soybean.

Boron toxicity in soil solution

Soil Research ◽  
1988 ◽  
Vol 26 (4) ◽  
pp. 605 ◽  
Author(s):  
RL Aitken ◽  
LE Mccallum
Keyword(s):  
Soil Solution ◽  
Soil Type ◽  
Dry Matter ◽  
Boron Concentration ◽  
Boron Toxicity ◽  
Controlled Environment ◽  
Dry Matter Accumulation ◽  
Undisturbed Soil ◽  
Toxicity Threshold ◽  
The Relationship

The relationship between soil solution boron concentration and the dry-matter accumulation and boron concentration in sunflower (Helianthus annuus cv. Hysun 31) was investigated in a 14-day study in a controlled environment. Plants were grown in each of six soils previously equilibrated with various levels of boron applied as H3BO3. The soil, wet to 10 kPa matric suction, was retained in polypropylene containers and the soil solution was extracted by centrifugation from the entire undisturbed soil volume immediately after the top growth had been harvested. Above a threshold of 1.9 �g B mL-1 in soil solution, yield reductions due to boron toxicity occurred. In the toxicity range there was a linear relationship between relative dry matter yield and log10[B] in soil solution. At high levels of boron, the relationship between boron concentration in plant tops and hot 0.01 M CaCl2-extractable boron depended on soil type, whereas the relationship between plant boron concentration and soil solution boron concentration did not depend on soil type. It is suggested that, at high levels of boron, plants were responding to soil solution boron (intensity), while hot 0.01 M CaCl2-extractable boron estimates a quantity factor. The results obtained indicate that the apparatus and technique used in this study could be used to derive toxicity threshold concentrations for a range of plant species.

Effect of water deprivation on feed intake, nutrient digestibility and nitrogen retention in sheep

1976 ◽  
Vol 86 (2) ◽  
pp. 431-433 ◽  
Author(s):  
N. P. Singh ◽  
T. More ◽  
K. L. Sahni
Keyword(s):  
Adverse Effect ◽  
Drinking Water ◽  
Feed Intake ◽  
Water Deprivation ◽  
Nitrogen Retention ◽  
Nutrient Digestibility ◽  
Sheep Grazing ◽  
Influence Of Water ◽  
Wool Yield ◽  
Sheep Production

The problem of sheep grazing in the deserts of Rajasthan is that animals do not get drinking water for 2–3 days at a time. Studies carried out at this Institute, on water deprivation in sheep, have indicated that sheep deprived of water for 72 h did not show any adverse effect on wool yield, in spite of the fact that water deprivation reduced feed intake (More & Sahni, 1972). The present experiment is a part of extensive studies carried out on water deprivation with particular reference to sheep production. The paper describes the influence of water deprivation on nutrient digestibility and nitrogen retention in sheep.

scholarly journals EFFECTS OF TISSUE BORON CONCENTRATIONS ON DRY MATTER ACCUMULATION IN BROCCOLI

HortScience ◽  
1990 ◽  
Vol 25 (8) ◽  
pp. 861a-861
Author(s):  
John C. Beaulieu ◽  
Dyremple B. Marsh
Keyword(s):  
Dry Matter ◽  
Leaf Tissue ◽  
Linear Increase ◽  
Silica Sand ◽  
Dry Matter Accumulation ◽  
Tissue Samples ◽  
Leaf Petiole ◽  
Boron Analysis ◽  
The Relationship ◽  
Nutrient Solutions

A greenhouse experiment was conducted to examine the relationship between tissue B concentration and dry matter accumulation in broccoli. `Pirate ' was grown in fine silica sand and supplied nutrient solutions containing 0.2, 0.8, 1.4, 2.0, 2.6, 3.2, 3.8, and 4.4 mg·liter-1 B. Plants were sampled for the 5th, 10th, and 15th fully expanded mature leaf, and plant material was collected' for dry matter measurement and boron analysis at each growth stage. The lowest specific leaf weights for the 5th, 10th, and 15th leaves were obtained with the 4.4 mg·liter-1 treatment. At maturity, leaf, petiole stalk, and shoot dry weights were lowest at 4.4 mg·liter-1 B. Treatments supplying less than 3.2 mg· liter-1 B, resulted in a notable decrease in tissue B concentrations from the 5th to the 15th leaf. There was a linear increase' in B concentration in all leaf tissue samples as B treatment increased. At maturity, optimum B concentrations of 531.5, 73.7, 29.8, and 64.6 mg·g-1 were found for the lamina, petiole, stalk, and head, respectively. These concentrations occurred in plants receiving treatment levels of 2.0-3.8 mg·liter-1 B.

scholarly journals High Density and Uniform Plant Distribution Improve Soybean Yield by Regulating Population Uniformity and Canopy Light Interception

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1880
Author(s):  
Cailong Xu ◽  
Ruidong Li ◽  
Wenwen Song ◽  
Tingting Wu ◽  
Shi Sun ◽  
...  
Keyword(s):  
Seed Yield ◽  
Dry Matter ◽  
Light Interception ◽  
Plant Distribution ◽  
Planting Density ◽  
Dry Matter Accumulation ◽  
Plant Spacing ◽  
Soybean Yield ◽  
The Relationship ◽  
Canopy Light Interception

Optimizing the spatial distribution of plants under normal conditions of water and fertilizer is widely used by farmers to improve soybean yield. However, the relationship between soybean yield and spatial plant distribution in the field has not been well studied. This study examined the effect of planting density and plant distribution pattern on soybean plant growth, yield components, canopy light interception, and dry matter accumulation. We also analyzed the relationship between photosynthetic rate, dry matter accumulation, and yield under different planting densities and plant distribution. A two year field experiment was conducted during the 2018 and 2019 soybean planting seasons. Two planting densities (1.8 × 105 and 2.7 × 105 plants ha−1) and two plant distribution patterns (uniform and non-uniform plant spacing) were tested. Higher planting density significantly increased the canopy light interception and dry matter accumulation during soybean growth, leading to increased soybean productivity. The seed yield of soybean under higher planting density was 22.8% higher than under normal planting density. Soybean planted under uniform spacing significantly reduced the differences plant-to-plant. Uniform plant spacing significantly increased the canopy light interception and dry matter accumulation of the soybean population. In addition, the coefficient of variation of seed weight per plant between individual plants under uniform plant distribution decreased by 71.5% compared with non-uniform plant distribution. Furthermore, uniform plant distribution increased soybean seed yield by 9.5% over non-uniform plant distribution. This study demonstrates that increasing planting density under uniform plant distribution can be useful to obtain higher seed yield without increasing other farm inputs.

scholarly journals Morphophysiological characteristics of guanandi fruit and seeds during ripening and harvesting time

2018 ◽  
Vol 53 (2) ◽  
pp. 212-220 ◽  
Author(s):  
Rosemeire Carvalho da Silva ◽  
Elisa Serra Negra Vieira ◽  
Maristela Panobianco
Keyword(s):  
Dry Matter ◽  
Morphological Characteristics ◽  
Dry Mass ◽  
Native Plant ◽  
Harvesting Time ◽  
Calophyllum Brasiliense ◽  
Relationship Of ◽  
The Relationship ◽  
Days After Anthesis ◽  
Mass Accumulation

Abstract: The objective of this work was to determine the relationship of the morphological and physiological characteristics of guanandi (Calophyllum brasiliense) fruit and seeds with ripening and harvesting time. The reproductive cycle of a native plant population, located in the coast of the state of Paraná, Brazil, was monitored from anthesis until fruit dispersion, during three years. Monthly harvests were performed, and the morphological and physical aspects (color, size, dry mass, and moisture content) of fruit and embryos were evaluated, as well as the physiological ones (germination and vigor) of seeds. The ripening process of guanandi seeds occurred between 200 and 240 days after anthesis (DAA), with anthesis peak in February and fruit dispersion in October. The maximum dry matter mass accumulation was not synchronized with the maximum physiological potential of the seeds. Germination potential was reached close to the middle of the maturation process, and maximum vigor at the end of the cycle. Fruit external color did not change from 110 DAA onwards. The morphological characteristics related to harvesting time are fruit pulp and embryo weakly adherent to the endocarp and to the tegument, respectively, as well as the dark-brown color of these tissues.

Effect of ammonium/nitrate ratio on growth and development of avocado plants under hydroponic conditions

2007 ◽  
Vol 87 (1) ◽  
pp. 99-103 ◽  
Author(s):  
P. Lobit ◽  
L. López-Pérez ◽  
R. Cárdenas-Navarro ◽  
V. C. Castellanos-Morales ◽  
R. Ruiz-Corro
Keyword(s):  
Carbon Content ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
Leaf Nitrogen ◽  
Dry Matter Accumulation ◽  
Hydroponic System ◽  
Architectural Analysis ◽  
Matter Production ◽  
The Relationship ◽  
Hydroponic Conditions

An experiment was carried out to study the effects of the proportion of ammonium (NH4+) and nitrate (NO3−) in the nutrient solution on avocado plants in a hydroponic system. Five treatments were applied, consisting of the following proportions of ammonium to nitrate ions in the solution: T0 = 0:4, T1 = 1:3, T2 = 2:2, T3 = 3:1 and T4 = 4:0 at a constant nitrogen concentration of 4 mM. After 4 months, the plants were harvested and fresh and dry matter accumulation, leaf area, and leaf nitrogen and carbon content were measured. An architectural description of the shoot (length, number of nodes and branching) was made. Dry matter of shoots and leaves all decreased with increasing NH4+ concentrations. In contrast, water content in aerial organs increased with NH4+ concentration. Nitrogen and carbon content and the relationship between dry matter production and leaf nitrogen were not significantly affected by the treatments. The architectural analysis showed that the shoots developed over time in one or two distinct growth units. While nitrogen form affected both growth units, the second one was more severely affected, showing decreased length, number of nodes, and branching when NH4+ concentration increased. Key words: Avocado, nitrogen, nitrate, ammonium, development

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