Calibration of GrassMaster II to estimate green and dry matter yield in Mediterranean pastures: effect of pasture moisture content

2016 ◽  
Vol 67 (7) ◽  
pp. 780 ◽  
Author(s):  
João Serrano ◽  
Shakib Shahidian ◽  
José Marques da Silva

Accurate assessment of standing pasture biomass in livestock production systems is a major factor for improving feed planning. Several tools are available to achieve this, including the GrassMaster II capacitance meter. This tool relies on an electrical signal, which is modified by the surrounding pasture. There is limited knowledge on how this capacitance meter performs in Mediterranean pastures. Therefore, we evaluated the GrassMaster II under Mediterranean conditions to determine (i) the effect of pasture moisture content (PMC) on the meter’s ability to estimate pasture green matter (GM) and dry matter (DM) yields, and (ii) the spatial variability and temporal stability of corrected meter readings (CMR) and DM in a bio-diverse pasture. Field tests were carried out with typical pastures of the southern region of Portugal (grasses, legumes, mixture and volunteer annual species) and at different phenological stages (and different PMC). There were significant positive linear relations between CMR and GM (r2 = 0.60, P < 0.01) and CMR and DM (r2 = 0.35, P < 0.05) for all locations (n = 347). Weak relationships were found for PMC (%) v. slope and coefficient of determination for both GM and DM. A significant linear relation existed for CMR v. GM and DM for PMC >80% (r2 = 0.57, P < 0.01, RMSE = 2856.7 kg ha–1, CVRMSE = 17.1% to GM; and r2 = 0.51, P < 0.01, RMSE = 353.7 kg ha–1, CVRMSE = 14.3% to DM). Therefore, under the conditions of this current study there exists an optimum PMC (%) for estimating both GM and DM with the GrassMaster II. Repeated-measurements taken at the same location on different dates and conditions in a bio-diverse pasture showed similar and stable patterns between CMR and DM (r2 = 0.67, P < 0.01, RMSE = 136.1 kg ha–1, CVRMSE = 6.5%). The results indicate that the GrassMaster II in-situ technique could play a crucial role in assessing pasture mass to improve feed planning under Mediterranean conditions.

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 481a-481 ◽  
Author(s):  
M. Rangappa ◽  
H.L. Bhardwaj

Sweet basil (Ocimum basilicum) is an important culinary herb in Virginia and other areas. The objective of this study, conducted during 1997, was to determine optimal N rate for fresh and dry matter yield. Seed of Broad Leaf sweet basil were direct-seeded on 18 June in rows 0.75 m apart in a RCBD design with 8 replications. Four N rates (0, 25, 50, and 75 kg N/ha) were used. Calcium nitrate (15.5% N) was used as the fertilizer source. All plants from 1-m row length from middle row of each plot were harvested by hand on 23 Sept. and fresh weights were recorded. The plant material was dried at 70°C for 48 h to record dry weights. The moisture content at harvest was calculated from fresh and dry weights. The fresh yields following 0, 25, 50, and 75 kg N/ha were 3.7, 5.4, 6.4, and 6.8 kg/m2, respectively. The yield difference between two highest N rates was not significant, however, both these rates had significantly higher yield than the two lowest rates. Similar results were also obtained for dry matter yields. The highest N rate of 75 kg N/ha resulted in significantly higher dry matter yield (1.3 kg/m2) as compared to the other three rates. The lowest dry matter yield was obtained after the control treatment (0.6 kg/m2). An opposite relationship between N rate and moisture content was observed when the highest moisture content resulted from control and 50 kg N/ha treatments. These results indicate that optimum N rate for sweet basil in Virginia is 50 to 75 kg/ha.


2017 ◽  
Vol 32 (2) ◽  
pp. 103-108 ◽  
Author(s):  
Michael J. Walsh ◽  
John C. Broster ◽  
Stephen B. Powles

AbstractIn Australia, widespread evolution of multi-resistant weed populations has driven the development and adoption of harvest weed seed control (HWSC). However, due to incompatibility of commonly used HWSC systems with highly productive conservation cropping systems, better HWSC systems are in demand. This study aimed to evaluate the efficacy of the integrated Harrington Seed Destructor (iHSD) mill on the seeds of Australia’s major crop weeds during wheat chaff processing. Also examined were the impacts of chaff type and moisture content on weed seed destruction efficacy. Initially, the iHSD mill speed of 3,000 rpm was identified as the most effective at destroying rigid ryegrass seeds present in wheat chaff. Subsequent testing determined that the iHSD mill was highly effective (>95% seed kill) on all Australian crop weeds examined. Rigid ryegrass seed kill was found to be highest for lupin chaff and lowest in barley, with wheat and canola chaff intermediate. Similarly, wheat chaff moisture reduced rigid ryegrass seed kill when moisture level exceeded 12%. The broad potential of the iHSD mill was evident, in that the reductions in efficacy due to wide-ranging differences in chaff type and moisture content were relatively small (≤10%). The results from these studies confirm the high efficacy and widespread suitability of the iHSD for use in Australian crop production systems. Additionally, as this system allows the conservation of all harvest residues, it is the best HWSC technique for conservation cropping systems.


2012 ◽  
Vol 52 (4) ◽  
pp. 486-493 ◽  
Author(s):  
Beata Feledyn-Szewczyk

Abstract The research was conducted from 2008 to 2010, and compared the influence of different weed control methods used in spring wheat on the structure of the weed communities and the crop yield. The study was carried out at the Experimental Station of the Institute of Soil Science and Plant Cultivation - State Research Institute in Osiny as part of a long-term trial where these crop production systems had been compared since 1994. In the conventional and integrated systems, spring wheat was grown in a pure stand, whereas in the organic system, the wheat was grown with undersown clover and grasses. In the conventional system, herbicides were applied two times in a growing season, but in the integrated system - only once. The effectiveness of weed management was lower in the organic system than in other systems, but the dry matter of weeds did not exceed 60 g/m2. In the integrated system, the average dry matter of weeds in spring wheat was 4 times lower, and in the conventional system 10 times lower than in the organic system. Weed diversity was the largest in spring wheat cultivated in the organic system. In the conventional and integrated systems, compensation of some weed species was observed (Viola arvensis, Fallopia convolvulus, Equisetum arvense). The comparison of weed communities using Sorenson’s indices revealed more of a similarity between systems in terms of number of weed species than in the number of individuals. Such results imply that qualitative changes are slower than quantitative ones. The yield of grain was the biggest in the integrated system (5.5 t/ha of average). It was 35% higher than in the organic system, and 20% higher than in conventional ones.


2017 ◽  
Vol 39 (4) ◽  
pp. 374-384
Author(s):  
Cesar Pedro Hartmann Filho ◽  
André Luís Duarte Goneli ◽  
Tathiana Elisa Masetto ◽  
Elton Aparecido Siqueira Martins ◽  
Guilherme Cardoso Oba

Abstract: This study evaluated the physiological potential of soybean seeds harvested during two seasons, on different maturation stages and subjected to different drying temperatures. The seeds were harvested at the maturations stages R7, R7 + 2, R7 + 3, R7 + 5, R7 + 6, R7 + 7, R7 + 10 and R7 + 12 days (55, 50, 45, 40, 35, 30, 25, and 20% of moisture content). For each maturation stage, seeds were divided into three samples: one sample was used to directly evaluate the physiological potential, and the others were dried at 40 °C and 50 °C, until reaching the moisture content of 11.5%. The physiological potential was evaluated through germination test, first germination count of germination, accelerated aging, modified cold, electrical conductivity and seedling emergence. The maximum physiological potential of seeds is achieved at the moisture content of 55%, the point that the dry matter is maximum. The seeds became tolerant to artificial drying approximately at the stage R7 + 7 days (30% of moisture content). Germination and vigor of the soybean seeds reduce as the drying temperature is increased from 40 °C to 50 °C, and this effect is enhanced when the seeds show moisture contents above 30%.


Author(s):  
Adata A. Jumbo ◽  
M. O. Wegwu ◽  
D. C. Belonwu ◽  
B. M. Onyegeme- Okerenta

Aims: This study investigated the physicochemical assessment of Rivers Kaa and Bodo in Ogoniland, as well as the proximate profile of selected fin and shell fish from these Rivers. Study Design: Random sampling. Place and Duration of Study: Kaa and Bodo communities of Ogoniland, between August and November 2014. Methodology: The physicochemical analysis; pH, temperature (T), biological oxygen demand (BOD), chemical oxygen demand (COD), dissolved oxygen (DO), total suspended solids (TSS), total dissolved solids (TDS), conductivity (C), salinity (S) and total hydrocarbon content (THC), were done. The results were compared to FEPA and APHA permissible limits. Proximate composition was determined using Association of Official Analytical Chemist standard analytical methods. Results: Physicochemical analysis results showed that T (26.5±.010), (26.8±.006) and TSS (8.68±.006), (12.5±.006) for Kaa were lower than Bodo (sp≤0.05), S (7.20±.021), (8.40±.010) and THC (0.25±.015), (3.00±.040) were both lower for Kaa than Bodo, at (p≤0.05), BOD was higher for samples collected from Bodo than samples collected from Kaa (188±.234), (259±.690). The TDS and Conductivity were both higher for samples from Bodo than those from Kaa, while pH and DO were higher for samples collected from Kaa than samples collected from Bodo. The moisture content for all samples collected from Kaa (63.7±.289), (72.5±.488), (75.1±.973), (67.4±.455), were significantly lower at p≤0.05 than the moisture content for samples from Bodo (68.7±.514), (80.6±.476), (86.2±.790), (74.5±.514) indicating that the samples from Kaa are better sources of protein, lipid, and energy than samples from Bodo. The protein, lipid, crude fibre, ash and dry matter content of all samples from Kaa were significantly higher (p≤0.05) than those for samples from Bodo. Conclusion: These findings suggest a contamination of the study sites particularly Bodo with petroleum products. Furthermore, it shows that the protein contents in all samples from Bodo were below the recommended standards, suggesting that the consumption of fishes from the study area particularly Bodo, is unhealthy.


2021 ◽  
Vol 43 (1) ◽  
pp. 378-384
Author(s):  
M. Baba ◽  
I. Lamir ◽  
I. Abdullahi ◽  
M. S. Sadique

The experiment was conducted at screen house of Centre for Dry land Agriculture, Bayero University Kano, in the year 2016. The objective of the study was to determine the effects of poultry manure and nitrogen rates from battery cage and deep litter systems on dry matter yield, morphological characteristics and forage quality of Columbus grass (Sorghum almum). Sorghum almum seeds were sown in 32 plastic containers (dimensions 26 cm height, 28 cm top width and 20cm base width) perforated at the bottom containing 12 kg mixture of sandy and loamy soil in ratio of 1:3. The treatments consisted of poultry manure from two production systems (Battery cage and Deep litter) and nitrogen rates (50, 60, 70 and 80 kgN/ha) in a 2x4 factorial combined in a completely randomized design. Parameters measured were dry matter yield, number of tillers and stem diameter at the late boot stage of Sorghum almum, in addition, forage quality parameters (CP, ADF NDF, digestible dry matter (DDM) dry matter intake as a percentage of body weight (DMI) and relative feud value (RFV)) were also evaluated. The results revealed no significant (p>0.05) difference between battery cage and deep litter fertilized Sorghum almum but deep litter fertilized Sorghum almum had numerically higher dry matter yield (5062.30 kg/ha) than battery cage (4400.40 kg/ha) Number of tillers and stem diameter were found to be significantly greater (p<0.05) in Deep litter (2.56 and5.70mm respectively) compared to Battery cage (1.13 and 5.08mm respectively. Both dry matter yield and stem diameter of Sorghum almum were significantly (p<0.05) highest at 80 kg N/ha. Crude protein was observed to be significant (P<0.05) in Sorghum almum fertilized with poultry manure from deep liter (11.35%) compared with buttery cage (10.05 %). The CP value was observed to increase with increased nitrogen rate with the highest value recorded at 80 kg N/ha (1.71%). Dry matter intake (us a percentage of body weight) was equally greater (p<0.05) in Sorghum album fertilized with deep litter (2.63%) compared to battery cage (2.49%). The value for NDF was significantly higher in sorghum almum fertilized with battery cage, while that of ADF was greater in deep litter it can be concluded that, Sorghum almum fertilized with manure from deep litter system produced better yield and nutritive value.


1975 ◽  
Vol 55 (1) ◽  
pp. 77-84 ◽  
Author(s):  
T. B. DAYNARD ◽  
R. B. HUNTER

Identical experiments were conducted at the Elora Research Station, near Guelph, Ontario in 1970 and 1971 with the objective of determining the relationships among whole-plant dry matter (DM) yield, whole-plant moisture content, and grain moisture content of corn (Zea mays L.) during the later part of the growing season. Each experiment involved eight commercial hybrids representative of the range in maturity, endosperm type, lodging resistance, and grain yield potential of corn hybrids grown commercially in central Ontario. The hybrids were sampled at weekly intervals over an 8-wk period beginning approximately 1 September; the sampled plants were divided into their leaf, stalk, husk, ear and grain components and oven-dried. Fresh and dry weights were used to calculate dry matter (DM) yields and "at harvest" moisture contents of the various components, and of the entire plant. Averaged across the eight hybrids, maximum DM yield was attained at whole-plant moisture content of 66–70%, and a grain moisture content of 45–50%. Among hybrids, 66% whole-plant moisture corresponded to a range in grain moisture content from 41 to 47%. Two additional experiments were grown also at Elora in 1970 and 1971 to evaluate the effects of harvest date on the DM yield and in vitro digestibility of corn plants and their component plant parts. Each experiment involved four representative commercial hybrids which were sampled at four equal time intervals during the month of September, and divided into grain, cob, husks (including shank) and stover (including leaves, leaf sheaths, stalks and tassels) for dry weight and in vitro digestibility measurement. Whole-plant DM digestibility was essentially constant over a range of whole-plant moisture from 76 to 56% in 1970, and from 76 to 64% in 1971. The consistency of whole-plant digestibility was the result of compensating changes in component yield and digestibility. A decrease in the digestibility of the stover, husks and cob with delayed harvest was compensated for by an increase in the proportion of grain in the whole-plant yield.


2005 ◽  
Vol 13 (2) ◽  
pp. 69-75 ◽  
Author(s):  
Roland Welle ◽  
Willi Greten ◽  
Thomas Müller ◽  
Gary Weber ◽  
Hartwig Wehrmann

Improving maize ( Zea mays L.) grain yield and agronomic properties are major goals for corn breeders in northern Europe. In order to facilitate field grain yield determination we measured corn grain moisture content with near infrared (NIR) spectroscopy directly on a harvesting machine. NIR spectroscopy, in combination with harvesting, significantly improved quality and speed of yield determination within the very narrow harvest time window. Moisture calibrations were developed with 2117 samples from the 2001 to 2003 crop seasons using six diode array spectrometers mounted on combines. These models were derived from databases containing spectra from all instruments. Spectrometer-specific calibrations cannot be used to predict samples measured on other instruments of the same type. Standard error of cross-validation ( SECV) and coefficient of determination ( R2) were 0.56 and 0.99%, respectively. Moisture standard errors of prediction ( SEPs) for the six instruments, using varying independent sample sets from the 2004 harvest, ranged between 0.59% and 0.99% with R2 values between 0.92 to 0.98. The six instruments produced the same dry matter predictions on a common sample set as indicated by high R2 and low biases among them, hence there was no need to apply specific standardisation algorithms. Moisture NIR spectroscopy determinations were significantly more precise than those obtained using the reference method. Analysis of variance revealed low least significant differences and high heritabilities. High precision and heritability demonstrate successful implementation of on-combine NIR spectroscopy for routine dry matter (yield) measurements.


2020 ◽  
Vol 180 ◽  
pp. 03007
Author(s):  
Albena Durakova ◽  
Adelina Bogoeva ◽  
Velichka Yanakieva ◽  
Tzvetana Gogova ◽  
Kornelia Choroleeva

The present study determined the physico-chemical parameters of the exotic fruit jujube (Ziziphus jujube mill) of Bulgarian origin – pH of 4.62, refractometric dry matter of 31.6 %, dry matter (in weight) of 36.78 %, TTA (total titratable acidity) – citric acid – of 0.67 %, 0.70 % malic acid, 65.95 % moisture, 0.78 % fibre, 1.41 % protein, 23.65 % carbohydrate, 0.24 % fat and energy value of 428.44 kJ/102.4 kcal. Equilibrium moisture content and monolayer moisture content were established for desorption concerning eight water activities in the 0.1 0.9 range and the temperatures of 10 °С, 25 °С and 40 °С. The coefficients of the modified Oswin, Chung-Pfost, Halsey and Henderson models were obtained statistically. The modified Halsey model is recommended as a description of the desorption isotherms of jujube (Ziziphus jujube mill) since it corresponds to the criteria for model assessment and suitability. Via BET model linearization, the values of the monolayer moisture content for desorption at the temperatures of 10 °С 5.41 % d.b., 25 °С – 4.65 % d.b. and 40 °С 5.08 % d.b were determined.


2018 ◽  
Vol 73 ◽  
pp. 05015
Author(s):  
Witdarko Yus ◽  
Mekiuw Yosehi ◽  
Sri Suryaningsih Ni Luh ◽  
Wahida

One of drying method applied in flour milling industry is pneumatic drying. Various kinds of variable both dried materials and drying process condition strongly influence the quality of drying result. Fineness Modulus (FM) and Water Rate are significant variables in defining the flour quality. The aim of this study is to identify the influence of dryer air temperature on FM and Moisture Content in pneumatic dryer process condition. Both variables have sufficiently big coefficient of determination value; therefore, it can be employed to predict well the fineness modulus and water rate of the flour.


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