scholarly journals Potassium fertilization: paradox or K management dilemma?

2015 ◽  
Vol 30 (2) ◽  
pp. 115-119 ◽  
Author(s):  
B. Bar-Yosef ◽  
H. Magen ◽  
A.E. Johnston ◽  
E.A. Kirkby
Keyword(s):  
Soil Chemistry ◽  
Detrimental Effect ◽  
Current Knowledge ◽  
Fertilizer Application ◽  
Soil Test ◽  
Review Of The Literature ◽  
Crop Response ◽  
K Fertilizer ◽  
K Fertilization ◽  
Over Time

AbstractIn 2014, Khan et al. presented evidence that soil exchangeable K (Exch-K) increases over time without addition of potassium (K) to the soil despite the removal of K in crops on a soil rich in montmorillonite and illite. The authors term this behavior ‘The potassium paradox’. From their review of the literature, the authors also report a lack of crop response to potassium chloride (KCl) fertilization. Close evaluation of these findings reveals that their observations can be interpreted and predicted using current knowledge of K in soil chemistry and its uptake by plants, and there is no paradox in K behavior in the soil–plant system. There is also no evidence of a detrimental effect of KCl on crop yield or quality. Their conclusion that the widely used Exch-K soil test is inadequate for managing K fertilization is discussed and some possible modifications to improve its performance are included. We believe that measurement of Exch-K is an essential and valuable tool and its use should be continued, along with improvements in recommending K fertilizer application.

scholarly journals Corn Stover Removal Responses on Soil Test P and K Levels in Coastal Plain Ultisols

2021 ◽  
Vol 13 (8) ◽  
pp. 4401
Author(s):  
Jeffrey M. Novak ◽  
James R. Frederick ◽  
Don W. Watts ◽  
Thomas F. Ducey ◽  
Douglas L. Karlen
Keyword(s):  
Coastal Plain ◽  
Nutrient Removal ◽  
Fertilizer Application ◽  
First Year ◽  
Soil Test ◽  
Concentration Data ◽  
Extractable P ◽  
K Fertilizer ◽  
Soil Test P ◽  
K Concentration

Corn (Zea mays L.) stover is used as a biofuel feedstock in the U.S. Selection of stover harvest rates for soils is problematic, however, because excessive stover removal may have consequences on plant available P and K concentrations. Our objective was to quantify stover harvest impacts on topsoil P and K contents in the southeastern U.S. Coastal Plain Ultisols. Five stover harvest rates (0, 25, 50, 75 and 100% by wt) were removed for five years from replicated plots. Grain and stover mass with P and K concentration data were used to calculate nutrient removal. Mehlich 1 (M1)-extractable P and K concentrations were used to monitor changes within the soils. Grain alone removed 13–15 kg ha−1 P and 15–18 kg ha−1 K each year, resulting in a cumulative removal of 70 and 85 kg ha−1 or 77 and 37% of the P and K fertilizer application, respectively. Harvesting stover increased nutrient removal such that when combined with grain removed, a cumulative total of 95% of the applied P and 126% of fertilizer K were taken away. This caused M1 P and K levels to decline significantly in the first year and even with annual fertilization to remain relatively static thereafter. For these Ultisols, we conclude that P and K fertilizer recommendations should be fine-tuned for P and K removed with grain and stover harvesting and that stover harvest of >50% by weight will significantly decrease soil test M1 P and K contents.

scholarly journals Broadening the Objectives of Future Potassium Recommendations

2020 ◽  
pp. 385-415
Author(s):  
Jeffrey J. Volenec ◽  
Sylvie M. Brouder ◽  
T. Scott Murrell
Keyword(s):  
Abiotic Stress Tolerance ◽  
Yield Response ◽  
Soil Test ◽  
K Uptake ◽  
K Fertilizer ◽  
The Usa ◽  
Use Efficiency ◽  
Fungal Associations ◽  
K Fertilization

AbstractPotassium (K) fertilizer recommendations for annual crops in the USA are generally founded in soil test results. The goal of this chapter is to highlight additional plant-related traits that may impact crop responses to K fertilization. This includes the role of tissue testing, the influence of luxury consumption, genetic improvement of K use efficiency, genotype × environment × management interactions on K uptake and yield, response to foliar K fertilization, intraplant K cycling, fungal associations and K uptake, the influence of K on crop quality, and the role of K in abiotic stress tolerance. Recognizing the potential role of these plant factors may help reconcile response inconsistencies based solely on soil test information, and improve future K recommendations. Finally, we hope to highlight knowledge gaps and opportunities for additional integrated soil–plant K research.

Application of seed-row potash to spring wheat grown on soils with high available potassium levels

2013 ◽  
Vol 93 (2) ◽  
pp. 271-277 ◽  
Author(s):  
Rigas Karamanos ◽  
Norm A. Flore ◽  
John T. Harapiak
Keyword(s):  
Spring Wheat ◽  
Critical Level ◽  
Triticum Aestivum L ◽  
Fertilizer Application ◽  
Soil Test ◽  
Western Canada ◽  
Days To Maturity ◽  
K Fertilizer ◽  
K Deficiency ◽  
Soil Test K

Karamanos, R., Flore, N. A. and Harapiak, J. T. 2013. Application of seed-row potash to spring wheat grown on soils with high available potassium levels. Can. J. Plant Sci. 93: 271–277. Two experiments were conducted at numerous locations across western Canada from 1990 to 1994 to ascertain the response of hard red spring (CWRS) wheat (Triticum aestivum L.) to seed-row applied K fertilizers. Soil test K levels at all sites (location×year combinations) exceeded the critical level for western Canada of 125 mg NH4OAc-extractable K kg−1, the concentration below which the probability of a K deficiency is high. In the first experiment, days to maturity and yield for wheat were statistically similar whether or not KCl was applied in the seed row. When the cultivar Roblin was grown significant (P<0.05) yield reductions as a result of seedrow placing low rates of potassium fertilizers were obtained. The second experiment showed that maturity and yield did not respond to treatments including KCl, K2SO4, or CaCl2 fertilizer applied in seed row. Furthermore, spring wheat responses for any of the preceding treatments were not different relative to the control (no K fertilizer applied). These findings bring into question the benefit of seed-row K fertilizer application to hard red spring (CWRS) wheat production on K-sufficient soils in western Canada.

scholarly journals RESPONSE OF FIVE LETTUCE TYPES TO K FERTILIZERS ON HISTOSOLS

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 665b-665
Author(s):  
N.M. El-Hout ◽  
C.A. Sanchez ◽  
S. Swanson
Keyword(s):  
Crop Production ◽  
Field Studies ◽  
Organic Soils ◽  
Soil Test ◽  
Nutrient Element ◽  
Optimal Production ◽  
Fertilizer Recommendations ◽  
K Fertilizer ◽  
Southern Florida ◽  
K Fertilization

Potassium is often considered the nutrient element most limiting to crop production on organic soils. On Histosols in southern Florida, K2SO4, rather than KCl, is often used for lettuce (Lactuca sativa L.) production to minimize the risk of salt injury. However, recent soil-test calibration research suggests that current K fertilizer recommendations for lettuce may be too high. Four field studies were conducted from 1989 to 1991 to evaluate the response of five lettuce types to K rate and source. The five lettuce types evaluated were leaf, bibb, boston, romaine (cos), and crisphead. Two sources of fertilizer K (K2SO4 and KCl) were evaluated at rates ranging from 0 to 600 kg K ha-1. Lettuce showed a minimal or no response to K fertilization. Potassium chloride had detrimental effects on lettuce only when applied at rates in excess of those required for optimal production. These studies showed that K fertilizer recommendations for lettuce produced on Histosols in Florida can be reduced. Furthermore, KCl, a more economical source, is suitable when the K is applied at appropriate rates.

scholarly journals Soil test crop response based phosphorus calibration study for bread wheat in Kofele District, West Arsi Zone Oromia, Ethiopia

2021 ◽  
pp. 20-25
Author(s):  
Abdurahman Husien ◽  
Tilahun Firomsa ◽  
Tilahun Abera
Keyword(s):  
Bread Wheat ◽  
Crop Productivity ◽  
Fertilizer Application ◽  
Yield Response ◽  
Future Research ◽  
Soil Test ◽  
Phosphorus Fertilizer ◽  
Crop Response ◽  
Arsi Zone ◽  
Calibration Study

Nowadays, a balanced fertilizer recommendation is of paramount importance in order to confirm the security and sustainably increase crop productivity for farmers and other stakeholders. Soil test crop response based phosphorus calibration study in two years (2017 and 2018) was done for bread wheat in kofele district with objectives to assess and evaluate yield response of bread wheat to phosphorus-fertilizer applications in soils that have initial high/medium/low levels of phosphorus on Eutric Vertisols. A composite soil samples collection were made in zigzag method from farmer’s land and analyzed for available P in order to identify the level of the required parameters in the soil to select farmland for actual experiment. Accordingly, phosphorus calibration study treatments include application of 0, 10,20,30,40 and 50 kg P ha-1 with recommended nitrogen 69 kg N ha-1 with RCBD design was used with two replications. The plot size of 5mx4m with a seed rate of 150 kg ha-1 and Ogolcho variety which had been recommended for the area was used. So that the result showed that phosphorus fertilizer application significantly affects yield and yield components of bread wheat. Similarly, phosphorous fertilizer application at different rates increased grain yield of bread wheat by 28 to 44% compared to the control. Furthermore, the study was revealed that phosphorus critical (Pc) point for bread wheat was 19, and phosphorus requirement factor was also 3.30. Therefore, future research should focus on verification of the result on farmland before disseminating the technology to the end-user.

Psychological and Cognitive Aspects of Borderline Intellectual Functioning

2017 ◽  
Vol 22 (3) ◽  
pp. 159-166 ◽  
Author(s):  
Bastianina Contena ◽  
Stefano Taddei
Keyword(s):  
Quality Of Life ◽  
Systematic Review ◽  
Intellectual Functioning ◽  
Clinical Impact ◽  
Review Of The Literature ◽  
Borderline Intellectual Functioning ◽  
General Quality ◽  
Meta Analyses ◽  
Over Time

Abstract. Borderline Intellectual Functioning (BIF) refers to a global IQ ranging from 71 to 84, and it represents a condition of clinical attention for its association with other disorders and its influence on the outcomes of treatments and, in general, quality of life and adaptation. Furthermore, its definition has changed over time causing a relevant clinical impact. For this reason, a systematic review of the literature on this topic can promote an understanding of what has been studied, and can differentiate what is currently attributable to BIF from that which cannot be associated with this kind of intellectual functioning. Using Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) criteria, we have conducted a review of the literature about BIF. The results suggest that this condition is still associated with mental retardation, and only a few studies have focused specifically on this condition.

scholarly journals Nutrient uptake, use efficiency and productivity of bread wheat (Triticum aestivum L.) as affected by nitrogen and potassium fertilizer in Keddida Gamela Woreda, Southern Ethiopia

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Temesgen Godebo ◽  
Fanuel Laekemariam ◽  
Gobeze Loha
Keyword(s):  
Triticum Aestivum ◽  
Grain Yield ◽  
Nutrient Uptake ◽  
Bread Wheat ◽  
Block Design ◽  
N Uptake ◽  
Fertilizer Application ◽  
Southern Ethiopia ◽  
K Fertilizer ◽  
Use Efficiency

AbstractBread wheat (Triticum aestivum L.) is one of the most important cereal crops in Ethiopia. The productivity of wheat is markedly constrained by nutrient depletion and inadequate fertilizer application. The experiment was conducted to study the effect of nitrogen (N) and potassium (K) fertilizer rates on growth, yield, nutrient uptake and use efficiency during 2019 cropping season on Kedida Gamela Woreda, Kembata Tembaro Zone Southern Ethiopia. Factorial combinations of four rates of N (0, 23, 46 and 69 kg Nha−1) and three rates of K2O (0, 30 and 60 kg Nha−1) in the form of urea (46–0-0) and murate of potash (KCl) (0-0-60) respectively, were laid out in a randomized complete block design with three replications. The results showed that most parameters viz yield, yield components, N uptake and use efficiency revealed significant differences (P < 0.05) due to interaction effects of N and K. Fertilizer application at the rate of 46 N and 30 kg K ha−1 resulted in high grain yield of 4392 kg ha− 1 and the lowest 1041 from control. The highest agronomic efficiency of N (52.5) obtained from the application of 46 kg N ha−1. Maximum physiological efficiency of N (86.6 kg kg−1) and use efficiency of K (58.6%) was recorded from the interaction of 46 and 30 kg K ha−1. Hence, it could be concluded that applying 46 and 30 kg K ha−1was resulted in high grain yield and economic return to wheat growing farmers of the area. Yet, in order to draw sound conclusion, repeating the experiment in over seasons and locations is recommended.

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