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Growth response of wheat plants as influenced by available phosphorus measured in Ohio and Bangladesh soils by soil solution and chemical extractant methods /Hannan, Muhammad Abdul January 1981 (has links)
No description available.
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The effect of crop rotation and tillage practice on soil moisture, nitrogen mineralisation, growth, development, yield and quality of wheat produced in the Swartland area of South AfricaWiese, Jacobus Daniel 03 1900 (has links)
Thesis (MScAgric)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: This study was done during 2010 and 2011 as a component study within a long-term
crop rotation/soil tillage trial that was started in 2007 at the Langgewens Research
Farm near Moorreesburg in the Western Cape Province of South Africa. The aim of
this study was to determine the effect of crop rotation and soil tillage on the soil
moisture content, mineral-N levels of the soil, leaf area index, chlorophyll content of
the flag leaf, biomass production, grain yield and grain quality of spring wheat
(Triticum aestivum L).
The experimental layout was a randomised complete block design with a split-plot
treatment design replicated four times. Wheat monoculture (WWWW), lupin-wheatcanola-
wheat (LWCW) and wheat-medic (McWMcW) crop rotation systems were
included in this study and allocated to main plots. This study was confined to wheat
after medic/clover, wheat after canola and wheat monoculture. Each main plot
was subdivided into four sub-plots allocated to four tillage treatments namely:
Zero-till (ZT) – soil left undisturbed until planting with a star-wheel planter
No-till (NT) – soil left undisturbed until planting and then planted with a no-till planter
Minimum-till (MT) – soil scarified March/April and then planted with a no-till planter
Conventional-till (CT) – soil scarified March/April, then ploughed and planted with a
no-till planter.
Soil samples were collected every two weeks from just before planting until before
harvest, from which gravimetric soil moisture and total mineral-N (NO3--N and NH4+-N)
were determined. Plant samples were collected every four weeks until anthesis,
starting four weeks after emergence. From these leaf area index and dry-matter
production were determined. Chlorophyll content and light interception were
measured at anthesis. At the end of the growing season the total biomass, grain
yield and grain quality was determined.
Crop rotations which included medics (McWMcW) or canola/lupins (LWCW) led to
higher mineral-N content of the soil at the start of the 2011 growing season when
compared to wheat monoculture, but did not have an effect on soil moisture.
Conservation tillage (minimum- and no-till) practices resulted in higher soil moisture
whilst conventional-till resulted in the highest mineral-N content for 2010. There was however no differences in mineral-N content between tillage methods for 2011,
whilst soil moisture content was affected in the same way as the previous year.
Both crop rotation and tillage influenced crop development and biomass
production. In general, increased soil disturbance together with wheat after medics
and wheat after canola resulted in better development of the wheat crop with
regards to dry matter production and leaf area index. The positive effect of medic
and canola rotations was also evident on chlorophyll content and light interception.
Grain yield was positively influenced by wheat after medics and wheat after canola,
with both systems out-yielding wheat monoculture in 2010 and 2011. Minimum- and
no-till resulted in the highest grain yield in both years. Crop rotation and tillage
practice showed no clear trends with regards to grain quality. This illustrated the
important effect of environmental conditions during grain-filling.
Environmental factors such as rainfall and temperature had significant effects in
both years of the study, but the importance and advantages of crop rotation,
especially with a legume crop such as medics included, was evident even though
this component study was done early in terms of the long-term study. The positive
effect of implementing conservation tillage practices such as minimum- and no-till
were also clearly shown in results obtained throughout this experiment. / AFRIKAANSE OPSOMMING: Die studie is gedurende 2010 en 2011 uitgevoer as ‘n deelstudie van ‘n langtermyn
grondbewerking- en wisselbouproef op die Langgewens proefplaas naby
Moorreesburg in die Wes-Kaap Provinsie van Suid-Afrika. Die doel van hierdie studie
was om die effek van grondbewerking en wisselbou op grondvog, minerale stikstof
in die grond, blaaroppervlakindeks, chlorofilinhoud van die blare, graanopbrengs en
-kwaliteit van lente koring (Triticum aestivum L) te kwantifiseer.
Die eksperiment is uitgelê as ‘n volledig lukrake blokontwerp met ‘n verdeelde
perseel ontwerp met vier herhalings. Wisselboustelsels wat aan hoofpersele
toegeken is sluit koring monokultuur (WWWW), lupien-koring-kanola-koring (LWCW)
en medic-koring (McWMcW) in. Grondbewerking is toegeken aan subpersele. Die
grondbewerkingsbehandelings het ingeslui:
Zero-bewerking (ZT) – die grond is onversteurd gelaat en koring is met ‘n
sterwielplanter geplant, Geen-bewerking (NT) – die grond is onversteur gelaat tot en
met planttyd waar koring met ‘n geenbewerking (no-till) planter geplant is,
Minimum-bewerking (MT) – die grond is in Maart/April met ‘n tandimplement bewerk
en met ‘n geen-bewerking planter geplant, Konvensionele-bewerking (CT) – die
grond is in Maart/April met ‘n tandimplement bewerk die grond is in Maar/April
geploeg met ‘n skaarploeg en met ‘n geenbewerking planter geplant.
Grondmonsters is elke twee weke versamel van net voor plant tot net voor oes.
Vanaf die versamelde monsters is die grondwaterinhoud grawimetries bepaal en
ook die totale minerale stikstofinhoud (NO3--N en NH4+-N). Plantmonsters is
vierweekliks versamel beginnende vier weke na opkoms tot en met antese.
Blaaroppervlakindeks en biomassaproduksie is bepaal. Die chlorofilinhoud en
ligonderskepping is tydens antese bepaal. Aan die einde van die groeiseisoen is
totale biomassa, graan opbrengs asook graankwaliteit bepaal.
Wisselboustelsels, wat medics (McWMcW) of kanola/lupine (LWCW) ingesluit het, het
‘n hoër minerale stikstofinhoud aan die begin van die 2011 groeiseisoen getoon.
Wisselbou het egter geen effek op grondvog gehad nie. Minimum- en geenbewerking
het ‘n hoër grondvoginhoud tot gevolg gehad, terwyl die persele onder
konvensionele bewerking ‘n hoër minerale stikstof inhoud gehad het in 2010. In 2011
was daar geen verskille in die minerale stikstofinhoud tussen verskillende die bewerkingsmetodes nie en grondvog gedurende 2011 is op dieselfde wyse as in
2010 beïnvloed.
Beide wisselbou en bewerkingsmetode het ‘n invloed gehad op gewasontwikkeling
en biomassaproduksie. Die algemene tendens was dat, soos grondversteuring
toegeneem het in die koring na medics en koring na kanola, het beter
gewasontwikkeling plaasgeving met betrekking tot droëmassaproduksie en
blaaroppervlakindeks. Die positiewe effek van wisselbou is ook waargeneem in die
chlorofilinhoud van die blare en die ligonderskeppingspotensiaal van die blaredak.
Graanopbrengs is positief beïnvloed deur die wisselboustelsel, met beide koring na
medics en koring na kanola wat hoër graanopbrengste as koring monokultuur vir
beide jare gelewer het. Die hoogste graanobrengs is ook gekry onder die minimumen
geen-bewerkingsbehandelings vir 2010 en 2011. Wisselbou en
bewerkingsmetodes het geen duidelike invloed op koringkwaliteit gehad nie. Dit is
‘n weerspieëling van die belangrike invloed van omgewingsfaktore gedurende die
korrelvulstadium van koring. Omgewingsfaktore soos reënval en temperatuur het betekenisvolle effekte in beide
jare van die studie gehad, maar die belang van ‘n wisselbou wat ‘n stikstofbinder
soos medics insluit, was reeds in hierdie vroeë stadiums van die langtermynproef
opvallend. Die positiewe effek van minimum- en geen-bewerking was ook duidelik
sigbaar gedurende die verloop van die studie. / The Western Cape Agricultural Trust for the opportunity and the finances to do this
study
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Predicting Wheat Growth Using the CSM-Cropsim-CERES - Wheat Crop ModelOttman, Michael 10 1900 (has links)
CSM-Cropsim-CERES -Wheat is a crop growth model that predicts crop development stages, among other things, using genetic coefficients for vernalization and photoperiod. We used this model to predict flowering date for 12 durum varieties seeded in trials at Maricopa and Yuma from 1998 to 2006. The difference between simulated and measured flowering date averaged 4 days without genetic coefficients and improved to 3.5 days if genetic coefficients for flowering and vernalization were included for each variety.
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The effect of zinc and soil ph on grain yield and nutrient concentrations in spring wheat cultivated on potted soilSingbo, Arnaud January 2018 (has links)
Thesis (MTech (Agriculture))--Cape Peninsula University of Technology, 2018. / Zinc deficiency on various soil types have been reported in arable soils of sub Saharan Africa (SSA) including South Africa. A pot trial was conducted at the Cape Peninsula University of Technology, Wellington campus to investigate the interaction of different application rates of Zn at various soil pH on the grain yield and quality of spring wheat in a completely randomized factorial design replicated three times. The four soil pH tested were: pHA: 5.1, pHB: 5.6, pHC: 6.1, pHD: 6.6 which correspond to lime application at 0, 0.5, 1 and 1.5 t/ha. Five Zn rates (Zn1: 3.5; Zn2: 4.5; Zn3: 5.5 Zn4: 6.5, and Zn5: 7.5 mg /kg soil which correspond to Zn1: 7; Zn2: 9; Zn3: 11; Zn4: 13 and Zn5: 15 kg /ha) were applied at two (planting and flowering) growth stages. Yield and yield component data collected were analyzed using SAS version 9.2 and means were separated by Duncun’s Multiple Range Test (DMRT). The results showed that grain yield and yield components were significantly affected by lime application pHC (6.1): 1t/ha at planting. Zn application at planting had no significant effect on the grain yield and yield components. However, at flowering, the simultaneous increase of Zn along with increase in lime positively affected grain yield and yield components. Plant analysis showed that at both stages (planting and flowering), Zn application, especially at pH 6.6, significantly increased P, K, Ca, Na, Mg Fe, Cu and B concentrations in wheat grain, but the concentrations of N, Mn, Zn and protein remained unaffected. Zn application had no effect on most nutrients due to the presence of lime. While the absence of lime, Zn4: 6.5mg/kg (corresponding to 13kg/ha) significantly increased the nutrients. In addition, Zn3: 5.5mg/kg (corresponding to 11kg/ha) promoted Zn absorption by grain in all treatments.
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Nitrogen in the soil-plant system of successive rainfed wheat crops under conventional cultivation.Otto, Willem Morkel. January 2002 (has links)
Soil mineral N and soil water content at planting, biomass accumulation, yield and grain quality parameters (hectolitermass and protein percentage) were measured on an unfertilized and recommended-N-application treatment during two consecutive growing seasons (1997-1998). The trials were planted in a fallow-wheat-wheat cropping system at three representative localities in the summer rainfall region of South Africa. High levels of available soil water and mineral N were measured following the fallow period preceding the start of the trials in 1997. For example, soil water content was 81.7%, 69.6%, and 78.2% of DUL at Bethlehem, Kroonstad and Petrusburg respectively. Although comparable total soil
profile water contents to 1997 were measured in 1998 at all three sites, the cultivation zone (0-400 mm) had a substantially lower soil water content. This was due to erratic rainfall distribution during the fallow
period, which prevented effective soil cultivation management, subsequent soil water conservation and residue decomposition. Undecomposed residue in the cultivation layer at planting appeared to affect availability of soil mineral N to the growing crop. At planting in 1998, undecomposed crop residue amounted to 53.6% at Bethlehem, 32.5% at Kroonstad and 46.9% at Petrusburg of that added at harvest in 1997. Soil mineral N was lower
at planting in 1998 compared to 1997 due to decomposing residue (C:N ratio of above 73) in the cultivation zone immobilizing soil mineral N. This reduced initial growth, N accumulation, yield, and grain protein percentage without additional fertilizer N. Distribution of soil mineral N showed notable
amounts in the 600-1200 mm soil layers, with limited changes over the trial period. This was linked to low root exploration of these soil layers (10-15% of total root distribution). The ratios of soil mineral NH(4+):N0(3)- for the different soil layers indicated similar values over the trial period.
Climatic data for the localities indicated differences in the amount and distribution of rainfall and temperatures during the study period, which influenced crop development, yield and grain protein percentage. At Bethlehem above average in-season rainfall was measured during 1997, at Kroonstad average rainfall and at Petrusburg below average in-season rainfall. Response to applied N at the localities varied in magnitude during 1997. Nitrogen application significantly increased N concentrations of plant components, N uptake, yield and grain protein percentage, although values for all these parameters were lower in 1998 than in 1997. Indeed higher
yields were produced in 1997 (mean=1.838 t ha(-1)) compared to 1998 (mean=0.980 t ha(-1)). A significant yield response to applied N was measured at the two higher yielding localities in both cropping years, but
there was no significant response at the lower yielding locality. The limiting factors appeared to be the availability of soil water and residual soil mineral N. From the calculated response functions, the variables soil water content at planting, soil mineral N content at planting, in-season rainfall, and added fertilizer N explained the bulk of the variations in grain protein percentage, plant N uptake, and yields. It was concluded that the present fertilizer N recommendation system for dryland wheat production,
which is based on fertilizer response curves for specific yield potentials, should be augmented by using initial soil mineral N and water contents in the profile measured prior to planting. / Thesis (M.Sc.Agric.)-University of Natal, Pietermaritzburg, 2002.
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Evaluation of Plant Growth Regulators on Wheat in Arizona, 1987Tickes, B., Ottman, M. J. 09 1900 (has links)
Plant growth regulators are applied to small grains to decrease lodging which can adversely affect crop growth and yield. Wheat is intensively managed in Arizona, and lodging can be a problem. Chlormequat and ethephon were applied at various rates and times in six studies in 1987 to evaluate their use on Arizona's semi -dwarf cultivars with respect to lodging plant height, yield components and grain yield The results indicated that growth regulators applied at the recommended rates and times may decrease plant height and decrease kernel weight. However, the influence of growth regulator treatments on tiller number, head number, kernel number, and grain yield was not demonstrated. The ambiguous results obtained suggest our efforts need to be directed toward documenting the extent of lodging in the state, studying the effects of lodging and predicting when lodging will occur.
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Late Season Water and Nitrogen Effects on Durum Quality, 1995 (Final)Ottman, M. J., Doerge, T. A., Martin, E. C. 10 1900 (has links)
Durum grain quality is affected by many factors, but water and nitrogen are factors that the grower can control. The purpose of this research was to determine 1) the nitrogen application rate required at pollen shed to maintain adequate grain protein levels if irrigation is excessive or deficient during grain fill and 2) if nitrogen applications during grain fill can elevate grain protein. Field research was conducted at the Maricopa Agricultural Center using the durum varieties Duraking, Minos, and Turbo. The field was treated uniformly until pollen shed when nitrogen was applied at rates of 0, 30, and 60 lbs/acre. During grain fill, the plots were irrigated based on 30, 50, or 70% moisture depletion. In a separate experiment, nitrogen fertilizer was applied at a rate of 30 lbs N/acre at pollen shed only, pollen shed and the first irrigation after pollen shed, and pollen shed and the first and second irrigation after pollen shed. Irrigation had no effect on grain protein level, although increasing nitrogen rates at pollen shed from 0 to 30 and 30 to 60 lbs N/acre increased protein by 1 percentage point. Nitrogen fertilizer application at the first irrigation after pollen shed increased grain protein content from 10.4 to 11.4% and application at the first and second irrigation after pollen shed increased grain protein content further to 11.9% averaged over varieties. Irrigation management during grain fill may not play as large a role in controlling grain protein content as was originally thought except perhaps on heavy soils, and nitrogen fertilizer application during grain fill may not be too late to increase grain protein content.
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Intensive Cereal Management for Durum Production, Buckeye, 1996Husman, S. H., Ottman, M. J. 10 1900 (has links)
No description available.
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Influence of Nitrogen Fertilizer Applied at Flowering on Durum Wheat Grain Yield and QualityKnowles, Tim C., Ottman, Michael J., Cramer, Rock 10 1900 (has links)
Application of nitrogen (N) fertilizer in conjunction with the irrigation event occurring closest to the flowering stage is effective in reducing the incidence of yellowberry and boosting grain protein levels of durum wheat. However, N applications at this time normally do not increase grain yield, except perhaps on very sandy soils. A field experiment was conducted to determine the profitability of applying 35 pounds of N per acre at flowering to durum wheat to avoid dockage for poor grain quality. Two treatments consisted of a check plot with no N applied at flowering and UAN 32 water run at a rate of 35 lbs. N /acre to basin irrigated durum wheat grown on a loamy sand soil. Maximum durum wheat grain yield (6157 lbs. /acre), protein concentration (13.7 %), and corrected income per acre ($480.31) was obtained with the N fertilizer application. In fact, N fertilization at flowering on this sandy soil increased durum wheat grain yield by 255 lbs. /acre compared to the unfertilized plot.
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Nitrogen Fertilization of Durum Based on Stem Nitrate, Buckeye, 1996Husman, S. H., Ottman, M. J. 10 1900 (has links)
No description available.
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