An evaluation of the properties of soil potassium influencing its supply by diffusion to plant roots in soil

1969 ◽  
Vol 73 (1) ◽  
pp. 1-14 ◽  
Author(s):  
R. Bagshaw ◽  
L. V. Vaidyanathan ◽  
P. H. Nye

SUMMARYK+ uptakes from forty-four arable soils from England by 1 cm portions of the roots of intact onion seedlings during 10 days growth were measured. A single-split-root arrangement was used, enabling the determination of uptake by known surface area of the root. Transpiration was restricted to make K+ diffusion in the soil the predominant supply mechanism. These were compared with calculated values using separately determined K+ diffusion coefficients in the soils.Two methods were followed, namely (a) measuring K+ diffusion to a hydrogen form of cation exchange resin paper and calculating diffusion coefficients assuming total depletion of the (ammonium acetate) exchangeable K+ at the resin paper: soil boundary; and (b) deriving diffusion coefficients from estimated values of the impedance factor and the measured K+ buffer power of each soil, for 50, 60, 90 and 100% depletion of the initial soil solution K+at the root:soil boundary. None of the predictions adequately accounted for the observed uptake. Calculations of the root:soil boundary concentrations showed a wide range of depletion. Soils with initial soil solution K+ in the range 0.04–0.4 μmoles/ml were depleted of the solution K+ to near zero or even less. A negative concentration of K+ in solution indicates the probable contribution of non-exchangeable K+. When the initial soil solution K+ was more than 0.4 μmoles/ml, the uptake of K+ could be accounted for by 30–85 % depletion at the root:soil boundary.Partial and multiple regression of the measured uptake on the initial exchangeable K+ content and the initial soil solution K+ concentration were calculated. A simple relationship between the uptake and the exchangeable K+ content accounted for about three-quarters the variance. The uptake was less closely associated with the K+ in solution or its ratio to Ca2+ + Mg2+ in solution. These correlations are discussed from the diffusion point of view and in relation to the usually reported correlations from pot experiments.Potato yield response to K+ fertilizer additions in field experiments are examined in relation to the supply of K+ by diffusion in the soils. When K+ uptake by 1 cm portion of onion root from the unfertilized soil exceeded l.2 μmoles/10 days, yield response to K+ addition became erratic and occasionally negative.

1963 ◽  
Vol 3 (8) ◽  
pp. 51 ◽  
Author(s):  
JD Colwell

Twenty two fertilizer experiments with wheat were carried out over a wide range of soil and environmental seasonal conditions in southern N.S. W. The effects of phosphorus and nitrogen fertilizers on the yield and composition of wheat are described. Seasonal environmental effects were examined by comparing the relative response to fertilizers of vegetative growth in the early spring with the final response of the harvested grain. Grain yield response to fertilizers is commonly restricted by seasonal conditions. Overcorrection of the phosphorus or nitrogen deficiencies may cause excessive early vegetative growth which exhausts soil moisture reserves before grain development has been completed. Loss of grain yields through this phenomenon is described locally as haying off. The chief danger in this respect seems to be from excessive nitrogen levels in the soil following a clover pasture. Assessments of economically desirable fertilizer applications on the basis of field experiments can only be based on statistical averages of seasonal conditions in each locality. The trials indicate, however, that the common application rate of superphosphate to wheat is inadequate in this region and should be at least doubled.


1967 ◽  
Vol 47 (3) ◽  
pp. 175-185 ◽  
Author(s):  
R. F. Bishop ◽  
C. R. MacEachern ◽  
D. C. MacKay

In field experiments, conducted at 18 locations during a 3-year period, tuber yields on zero-P plots ranged from 49.7–95.5% of those obtained with optimum P fertilization. Each of three chemical methods used to estimate available soil P showed a wide range of values for the different locations.When Bray's modification of the Mitscherlich equation was used to express the relationship between soil test values and yield response to applied P, there were appreciable differences in c1 values which varied with soil series and soil test methods.Polynomial response curves showed that, irrespective of the chemical method used, if soils were grouped on the basis of available P into "high", "medium" and "low" classes, response to applied P was much less in the high than in the medium and low classes. Response curves also showed that both P requirements and maximum yields varied with different soil series.


2018 ◽  
Vol 45 (2) ◽  
pp. 82-86 ◽  
Author(s):  
F.D. Morla ◽  
O. Giayetto ◽  
E. M. Fernandez ◽  
G. A. Cerioni ◽  
C. Cerliani

ABSTRACT Plant density is one of the most important management factors affecting the peanut growth, modifying the capacity to capture radiation, water and nutrients. Peanut yield response to increased plant density changes according to environmental conditions, the genotype used, and planting date. Therefore, the optimum plant density (OPD) may vary with location. The aim of this project was (i) to fit the Mitscherlich's equation of diminishing productivities to the yield response of runner-type peanuts to increasing plant density under different growing conditions in the peanut growing region of Cordoba Argentina; and (ii) validate this model with independent experimental data. The first stage was based on the analysis of data from different projects of plant densities carried out in the peanut growing area of Córdoba. This information was adjusted to the decreasing yield equation and the OPD was calculated. For validation, a field experiment was conducted during the 2013/14 and 2014/15 growing seasons under irrigated and rain-fed conditions where pod yield was evaluated for 5, 12, 18, 25 and 36 plants/m2. No interaction was detected between soil moisture conditions and plant density. Yield response to plant density had a high degree of fitness for a wide range of environmental and crop conditions. In field experiments, the peanut yield decreased only at the lowest plant density (5 plants/m2). Yield response to density adjusted to the Mitscherlich equation indicated that OPD ranged from 10.5 to 24.8 plants/m2. Using a single adjustment equation y = 1(1 – e−0.1784x), OPD was estimated to be 16.8 plants/m2 at harvest (11.7 plants per linear meter in 0.7 m between rows) for the peanut growing region of Cordoba. This approach can be a valuable input, along with other variables to analyze, when choosing peanut sowing density.


1987 ◽  
Vol 67 (4) ◽  
pp. 877-891 ◽  
Author(s):  
D. C. MaCKAY ◽  
J. M. CAREFOOT

A series of 10 field experiments conducted over a 4-yr period (1973–1976) on three of the most important Brown Chernozemic soils in the irrigated area of southern Alberta gave no significant yield responses to applied K (at rates of 0, 50, 100 and 150 kg ha −1 in 1973 and 0, 127, 254 and 508 kg ha−1 in the other years), using potato (Solanum tuberosum L.) as the test crop. The experiments included several cultivars, a variety of growing conditions, and diverse cropping histories. In addition, the K concentration of uppermost mature leaf blades obtained at the 10%-bloom stage were only slightly affected by K treatments, except in 1 yr (1975). The increased K uptake in 1975 was related to greater precipitation before irrigation was applied (66, 99 and 94 mm, respectively) during April, May and June in comparison with the long-term average of 32, 54 and 76 mm. The effects of early-season soil moisture stress were partially confirmed in a controlled environment (CE) experiment in which maintenance of soil water potentials between −30 and −20 kPa throughout the season caused greater uptake of added K in comparison with soil moisture stress in the 0–15 cm zone prior to the 10%-bloom stage. Yields of tubers were depressed with the stressed treatment, but there was no yield response to added K. Leaf analyses from the field experiments indicate that the critical K level of 43 g kg−1, which was established earlier for the Russet Burbank cultivar growing on Podzol soils is too high for irrigated Chernozemic soils, and that 30 g kg−1 would be a more valid tentative value. In a second CE experiment, designed to quantify the fate of applied K during intensive cropping, no yield responses to K applications were obtained with alfalfa on a coarse-textured Cavendish sandy loam during a 2-yr period. With no applied K, crop uptake reduced exchangeable K levels throughout the entire profile (66 cm) by about 20%. Thirty percent of the K removed by the crop originated from nonexchangeable soil K. With the highest K rate (450 kg ha−1 applied twice), 50% could be attributed to plant uptake, 15% to increased exchangeable K, and 35% to fixation in the nonexchangeable form. It is concluded that response to applied K on irrigated Brown and Dark Brown Chernozemic soils of southern Alberta is unlikely, even with intensive cropping, for some time in the future. A practical strategy for producers could be to apply moderate rates of K as a conservation measure when economic conditions are favorable and to rely on soil reserves in times of financial pressures. Key words: K-release, K-fixation, leaf analysis, fertilizer K requirements, soil water stress, K deficiency


1990 ◽  
Vol 30 (3) ◽  
pp. 395 ◽  
Author(s):  
RC Muchow ◽  
JD Sturtz ◽  
MF Spillman ◽  
GE Routley ◽  
S Kaplan ◽  
...  

Field experiments were conducted at Berrimah, Douglas Daly and Katherine in the Northern Territory (NT) during the 1987-88 and 1988-89 wet seasons to obtain yield data for kenaf (Hibiscus cannabinzis L. cv. Guatemala 4) grown under rainfed and irrigated conditions. Under rainfed conditions, maximum stem yield was obtained from sowings early in the wet season. Yield decreased with delay in sowing until the late-December-January period. The maximum rainfed stem yield at Katherine in an above-average rainfall season was 18 400 kg/ha. The maximum yield in a below average rainfall season was 11 700 kg/ha at Katherine, 9200 kg/ha at Douglas Daly and 9400 kg/ha at Berrimah. The applicability to the NT of growth and yield relationships established for irrigated kenaf in the Ord Irrigation Area (OIA) was assessed. The yield potential under irrigated conditions in the NT (21 600 kg/ha at 131 days after sowing) was higher than that reported elsewhere in Australia for the same growth period, but similar to that reported elsewhere for longer growth duration (180-300 days). In the NT, in contrast to the OIA, stem yield showed little or no response to N fertilisation. Stem yield was not related to N uptake, and at high levels of N application, there was marked N accumulation in the stem. Kenaf was able to accumulate up to 110 kg N/ha from the soil reserve where no N was applied. The yield response to plant density varied with the yield level and was similar to that in the OIA. Bark and core yield could be estimated directly from biomass, and indirectly from stem length and plant density, over a wide range of yield levels and cultural conditions. It was concluded that data relating to yield potential and response to N fertilisation cannot be transferred directly from the OIA to the NT.


Agriculture ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 752
Author(s):  
Aliasghar Montazar ◽  
Daniel Geisseler ◽  
Michael Cahn

Nitrogen (N) and irrigation water must be effectively used in mineral soils to produce carrots with high yield and minimal environmental impact. This study attempts to identify optimal N and irrigation management practices for low desert carrot production in California by investigating consumptive water use and N uptake and removal rates in fresh market and processing carrots. Field experiments were conducted at the University of California Desert Research and Extension Center and nine farmer fields during two growing seasons. The actual evapotranspiration (ETa) was measured using the residual energy balance method with a combination of surface renewal and eddy covariance equipment. Crop canopy coverage, actual soil nitrate-N from multiple depths as well as total N percentage, dry matter, and fresh biomass in roots and tops were measured over the growing seasons. The length of the crop season had a wide range amongst the experimental sites: from a 128-day period in a processing carrot field to as long as 193 days in a fresh market carrot field. The seasonal ETa varied between 305.8 mm at a silty loam furrow irrigated processing carrot field and 486.2 mm at a sandy clay loam sprinkler irrigated fresh market field. The total N accumulated at harvest ranged between 205.4 kg ha−1 (nearly 52% in roots) and 350.5 kg ha−1 (nearly 64% in roots). While the mean value of nitrogen removed by carrot roots varied from 1.24 to 1.73 kg N/Mg carrot roots, it appears that more N was applied than was removed by carrot roots at all sites. Within the range of N application rates examined at the experimental sites, there was no significant relationship between carrot fresh root yield and N application rate, although the results suggested a positive effect of N application on carrot yield. Sufficient soil N availability over the growing season and the lack of significant yield response to N application illuminated that optimal N rates are likely less than the total amounts of N applied at most sites.


2000 ◽  
Vol 51 (8) ◽  
pp. 971 ◽  
Author(s):  
J. M. Morgan

The effect of water stress on yield increases produced by breeding for an osmoregulation gene (or) was examined using both backcross-bred lines (produced using allele identification in pollen grains) and inbred lines (produced using leaf tests). Yields were measured in 39 field experiments spanning 8 seasons. These included experiments where water was supplied through drip irrigators and rain excluded with a mobile shelter. Several approaches to the measurement of stress environment were examined. The commonly used site mean yield, although most accessible and so utilising the most data, was least effective in explaining variation in yield response. Comparatively high efficiency (84%) could be achieved using measurements of rainfall or evaporative demand for specific periods of crop ontogeny, but this suffered the limitation of being season or treatment specific. The results did, however, demonstrate the value of the pollen selection method in increasing yield under conditions of reduced water supply. In keeping with past climatic analyses, and with the theory underlying variations in leaf water potential to which osmoregulation responds, an index incorporating water supply and evaporative demand accounted well for the yield increase (85%) over the wide range of seasons and treatments examined. It requires inputs of available soil water at sowing, rainfall, and free-water evaporation during the growing period, together with sowing and anthesis dates. The index was used to assess potential yield responses in the various climates covered by the Australian wheatbelt. Greatest potential lay at the drier, inland, margins especially where soils are lighter and water-holding capacities lower.


2015 ◽  
Vol 5 (1) ◽  
pp. 606-620
Author(s):  
Mahtali Sbih ◽  
Zoubeir BENSID ◽  
Zohra BOUNOUARA ◽  
Fouad DJAIZ ◽  
Youcef FERRAG

The goal of fertilization is to meet the nutritional needs of plants by completing the supply of soil nutrients in an economically profitable and environmentally friendly. Achieving on-farm optimum economic crop yields of marketable quality with minimum adverse environmental impact requires close attention to fertilization guide. The recommendations seek to do this by ensuring that the available supply of plant nutrients in soil is judiciously supplemented by additions of nutrients in fertilizers. The objective is that crops must have an adequate supply of nutrients, and many crops show large and very profitable increases in yield from the correct use of fertilizers to supply nutrients. The main objective of this work is to establishing a reference guide of fertilization of vegetable crops and cereal in Algeria. To meet this objective, we have processes in two steps: 1) Establishment of theoretical fertilizer recommendation from international guide of crop fertilization; 2) Validation of these developed theoretical fertilizer recommendation by trials in the fields. Sixteen fertilization guides of vegetable crops from the Canadian provinces (5 guides), USA (10 guides) and countries of northern Europe England (1 guide). Generally, the rating of these recommendation is ranging from poor soil to soil exceedingly rich; however, the numbers of fertility classes are very different. Indeed, Quebec Ontario, Minnesota, Wisconsin New England, Maryland and Kentucky and Florida guides are subdivided into 5 fertility classes, ranging from poor soil to soil exceedingly rich. The recommendation of New Brunswick and Manitoba contain six classes. The recommendation of Michigan, Nova Scotia and England contain 10 and 7 fertility classes respectively. The recommendation fertilizer of New York and New Jersey have 3classes. Unlike the systems of fertilization recommendation mentioned above, the recommendation fertilizer of Pennsylvania is based on continuous models of P, K and contains 34 classes for P and 22 classes K. Then we standardized the P soil analysis with conversion equations (Olsen method) and units of measurement (kg/ha, mg/kg…).Following this procedure we transformed discontinued systems of fertility classes in to continuous models to facilitate comparison between the different fertilization recommendation models in one hand, in other hand to obtain critical value (CV).Finally, we used statistics of the conditional expectation in order to generate the theoretical recommendation fertilization guide of fertilization with 7 fertility classes (VL, L, M, MH, OP, H and VH). The next step was calibrating soil tests against yield responses to applied nutrient in field experiments. A database (not published data) from agriculture and agri-food Canada, were used. Production of pumpkin responded positively and significantly to P or K soil fertility levels, increases being observed with P more often than with K. According to the Cate-Nelson methods, the critical value of Olsen-P in the top 20 cm of soil was about 25 mg/kg: at values of greater than or equal to 25 mg/kg, crops achieved about 80% of their maximal yield in the absence of fertilizer application. The CV of K in soil for this crop was about 140 mg/kg. The CV found was very close to this generated by the theoretical method for recommendation of fertilization guide. Finally, we used the procedure of Cope and Rouse in both sides of the CV in order to make subdivisions of different groups of soil fertility. One calibrates the soil-test value against yield response to tile nutrient to predict fertilizer requirement.


Weed Science ◽  
1979 ◽  
Vol 27 (5) ◽  
pp. 497-501 ◽  
Author(s):  
C. D. Boyette ◽  
G. E. Templeton ◽  
R. J. Smith

An indigenous, host-specific, pathogenic fungus that parasitizes winged waterprimrose [Jussiaea decurrens(Walt.) DC.] is endemic in the rice growing region of Arkansas. The fungus was isolated and identified asColletotrichum gloeosporioides(Penz.) Sacc. f.sp. jussiaeae(CGJ). It is highly specific for parasitism of winged waterprimrose and not parasitic on creeping waterprimrose (J. repensL. var.glabrescensKtze.), rice (Oryza sativaL.), soybeans [Glycine max(L.) Merr.], cotton (Gossypium hirsutumL.), or 4 other crops and 13 other weeds. The fungus was physiologically distinct from C.gloeosporioides(Penz.) Sacc. f. sp.aeschynomene(CGA), an endemic anthracnose pathogen of northern jointvetch[Aeschynomene virginica(L.) B.S.P.], as indicated by cross inoculations of both weeds. Culture in the laboratory and inoculation of winged waterprimrose in greenhouse, growth chamber and field experiments indicated that the pathogen was stable, specific, and virulent in a wide range of environments. The pathogen yielded large quantities of spores in liquid culture. It is suitable for control of winged waterprimrose. Winged waterprimrose and northern jointvetch were controlled in greenhouse and field tests by application of spore mixtures of CGJ and CGA at concentrations of 1 to 2 million spores/ml of each fungus in 94 L/ha of water; the fungi did not damage rice or nontarget crops.


Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.


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