Availability of single spring applications of three sulphur fertilizer sources to grass under humid weather conditions

2009 ◽  
Vol 89 (4) ◽  
pp. 511-519
Author(s):  
C G Kowalenko

Field experiments were conducted to compare the effectiveness of single spring applications of three sulphur (S) fertilizers (powdered and granulated elemental S, and granulated sparingly soluble gypsum) to supply S to tall fescue grass (Festuca arundinacea 'Festorina') under humid weather conditions of coastal British Columbia. The treatments were three rates (30, 60 and 90 kg S ha-1) of each of the three fertilizers and control (No S) in three plots initiated in1997, 1998 and 1999 in different locations in an uniformly managed field. The relative effectiveness of the fertilizers was detected by plant uptake of S since the site was only marginally S deficient resulting in only occasional yield increases. The fertilizers were also evaluated by the increase of inorganic sulphate in the soil. The plant and soil measurements showed that S was available to the plant earlier from the granular gypsum than the elemental forms, and the powdered form was available slightly earlier than the granular form of elemental S. Some uptake of all three fertilizers occurred early in the season, i.e., by the first cut of the crop, showing that elemental S was oxidized relatively quickly. The delayed uptake of S from the granulated elemental S compared with the powdered form reflected the need for the granule to disintegrate before it could be oxidized in the soil. This study showed that S is not always available in soils at the time it is required by plants within a growing season of multiple-cut grass. Knowing the pattern of the release of S from various fertilizer forms in relation to within-season variations of soil S availability and plant requirement of S can provide the basis for optimum amendment decisions.Key words: S fertilizers, elemental S, sulphate-S, crop response, crop S uptake, soil sulphate, SulFer 95

2000 ◽  
Vol 80 (1) ◽  
pp. 105-112 ◽  
Author(s):  
S. S. Malhi ◽  
K. Heier ◽  
E. Solberg

Two field experiments were conducted from 1993 to 1995 to compare the effectiveness of various cumulative elemental S and sulphate-S fertilizer applications in increasing dry matter yield (DMY) and S uptake of forage grass. In exp. 1, one sulphate-S (Na2SO4) and two elemental S (Agric-Grade 0-0-0-95 and Tiger 90) fertilizers were applied annually to grass in mid to late April at 10, 20, 30, 40 and 50 kg S ha−1 rates. The increase in DMY from S application was significantly lower with elemental S fertilizers than with Na2SO4 in the first and second years, but in the third year elemental S fertilizers had DMY increase similar to Na2SO4 In exp. 2, a number of elemental S and sulphate-S fertilizers were applied annually to grass in mid- to late April at 15 kg S ha−1 rate. There was a marked increase in DMY from S application in all the 3 yr with the three sulphate-containing S fertilizers (Na2SO4, K2SO4 and CaSO4). When elemental S fertilizers were used, only Turf-Grade 0-0-0-95 increased DMY in all the 3 yr and it produced DMY increase similar to the sulphate-S fertilizers in the third year. Elemental S Prills did not produce any significant increase in DMY in any of the 3 yr. Other elemental S fertilizers [e.g., Elemental S Powder, Agric-Grade 0-0-0-95 and Tiger 90] increased DMY in the third year only, but this increase was still less than the sulfate-S fertilizers. Turf-Grade 0-0-0-95 (with smaller granules) produced greater DMY increase than Agric-Grade 0-0-0-95 (with larger granules) in all the 3 yr (though significant in the third year only). The S fertilizers that contained small amounts of sulphate-S in addition to elemental S were generally more effective in increasing DMY than the similar fertilizers containing only elemental S. The increase in S uptake from applied S in grass showed usually similar trends as DMY increase. In conclusion, the results suggest that some elemental S fertilizers can be as effective in increasing forage DMY on perennial grass as sulfate-S fertilizers. However, depending upon soil type and climatic conditions two or more growing seasons may be needed for S in the elemental S fertilizers to become fully available to the plants. Key words: Elemental S fertilizers, forage yield, grassland, sulphate-S fertilizers, sulphur uptake


2020 ◽  
Vol 80 (2) ◽  
pp. 133-146
Author(s):  
L Zhang ◽  
Z Zhang ◽  
J Cao ◽  
Y Luo ◽  
Z Li

Grain maize production exceeds the demand for grain maize in China. Methods for harvesting good-quality silage maize urgently need a theoretical basis and reference data in order to ensure its benefits to farmers. However, research on silage maize is limited, and very few studies have focused on its energetic value and quality. Here, we calibrated the CERES-Maize model for 24 cultivars with 93 field experiments and then performed a long-term (1980-2017) simulation to optimize genotype-environment-management (G-E-M) interactions in the 4 main agroecological zones across China. We found that CERES-Maize could reproduce the growth and development of maize well under various management and weather conditions with a phenology bias of <5 d and biomass relative root mean square error values of <5%. The simulated results showed that sowing long-growth-cycle cultivars approximately 10 d in advance could yield good-quality silage. The optimal sowing dates (from late May to July) and harvest dates (from early October to mid-November) gradually became later from north to south. A high-energy yield was expected when sowing at an early date and/or with late-maturing cultivars. We found that Northeast China and the North China Plain were potential silage maize growing areas, although these areas experienced a medium or even high frost risk. Southwestern maize experienced a low risk level, but the low soil fertility limited the attainable yield. The results of this paper provide information for designing an optimal G×E×M strategy to ensure silage maize production in the Chinese Maize Belt.


2018 ◽  
Vol 1 (94) ◽  
pp. 38-44
Author(s):  
А.M. Malienkо ◽  
N.E. Borуs ◽  
N.G. Buslaeva

In the article, the results of research on the methodology for conducting studies with corn culture under various methods of sowing and weather conditions. The aim of the research was to establish and evaluate the reliability and high accuracy of the experiment, with a decrease in the area's acreage and taking one plant per repetition. Based on the results of the analysis of biometric parameters and yields, the possibility of sampling from 5 to 108 plants was established statistically and mathematically to establish the accuracy of the experiment. The established parameters of sites in experiments with maize indicate the possibility of obtaining much more information from a smaller unit of area, that is, to increase labor productivity not only with tilled crops. This is the goal of further scientific research with other field crops taking 1 plant of repetitions, observing the conditions of leveling the experimental plot according to the fertility of the soil and sowing seeds with high condition. The data obtained give grounds for continuing research on the minimum space required and the sample in the experiments.


2016 ◽  
Vol 04 (04) ◽  
pp. 1650027
Author(s):  
Rong ZHU

Analysis of the meteorological conditions for atmospheric pollutant dispersion before and after the 2014 APEC meeting shows very significant effects of air pollution prevention and control measures on the meeting. It proves that the proper measures to control air pollution in the Beijing-Tianjin-Hebei Region are: establishing a regional emergency response mechanism to reduce emissions in the case of heavy air pollution, strengthening the local emergency response measures for emission reduction, and enhancing the early warning system for weather conditions conducive to heavy air pollution.


PEDIATRICS ◽  
1989 ◽  
Vol 84 (1) ◽  
pp. 157-164
Author(s):  
Christine Powell ◽  
Sally Grantham-McGregor

Two studies were made of home visiting and psychosocial stimulation with deprived urban children in Jamaica. The aim was to determine the relative effectiveness of different frequencies of visiting on the children's developmental levels and the feasibility of integrating the model into government primary health care services. Health paraprofessionals supervised by a nurse from a local health center conducted the intervention. In the first study, 152 children aged 6 to 30 months were assigned to groups visited biweekly, monthly, or not at all by area of residence. The biweekly group showed small but significant increases in scores on the Griffiths Mental Development Scales (developmental quotient) and performance subscale compared with the monthly and control groups, whereas no benefit was shown in the Griffiths scores of the monthly group. In the second study, 58 children aged 16 to 30 months from the same neighborhoods were randomly assigned to weekly visited and control groups. The group visited weekly showed marked improvements in the performance and hearing and speech subscales as well as the developmental quotient scores. The results indicate that as the frequency of visiting increases from none through monthly and biweekly to weekly, the benefits increase as well.


1997 ◽  
Vol 11 (3) ◽  
pp. 515-519 ◽  
Author(s):  
Julio A. Scursoni ◽  
Emilio H. Satorre

The objective of this paper was to evaluate the effect of preplant applications of trifluralin on barley stand and yield, and control of grass weeds in field experiments during 1992 and 1993. Factors examined were: (1) crop planting patterns (conventional drill with rows 15 cm apart and deep-seeder drill with rows 25 cm apart), (2) herbicide application times (22 d before sowing and immediately before sowing), and (3) herbicide application. During 1993, hand-weeded plots also were established. Trifluralin applied preplant at 528 g ai/ha reduced weed density and biomass. Weed control was higher under conventional planting than under the deep planting pattern, and there was no effect of the time of application on herbicide efficacy. There was no herbicide injury to the crop, and grain yield was higher in treated than in untreated plots due to successful weed control.


2019 ◽  
Vol 116 (10) ◽  
pp. 4156-4165 ◽  
Author(s):  
Sören R. Künzel ◽  
Jasjeet S. Sekhon ◽  
Peter J. Bickel ◽  
Bin Yu

There is growing interest in estimating and analyzing heterogeneous treatment effects in experimental and observational studies. We describe a number of metaalgorithms that can take advantage of any supervised learning or regression method in machine learning and statistics to estimate the conditional average treatment effect (CATE) function. Metaalgorithms build on base algorithms—such as random forests (RFs), Bayesian additive regression trees (BARTs), or neural networks—to estimate the CATE, a function that the base algorithms are not designed to estimate directly. We introduce a metaalgorithm, the X-learner, that is provably efficient when the number of units in one treatment group is much larger than in the other and can exploit structural properties of the CATE function. For example, if the CATE function is linear and the response functions in treatment and control are Lipschitz-continuous, the X-learner can still achieve the parametric rate under regularity conditions. We then introduce versions of the X-learner that use RF and BART as base learners. In extensive simulation studies, the X-learner performs favorably, although none of the metalearners is uniformly the best. In two persuasion field experiments from political science, we demonstrate how our X-learner can be used to target treatment regimes and to shed light on underlying mechanisms. A software package is provided that implements our methods.


2021 ◽  
Vol 210 (07) ◽  
pp. 55-65
Author(s):  
Larisa Ikoeva ◽  
Oksana Haeva

Abstract. The purpose of the work is to study the influence of the growth regulator “Regoplant” and microfertilizer “Ultramag Kombi” on the photosynthetic productivity of the potatoes of the Barna variety based on the results of field experiments in the forest-steppe zone Republic of North Ossetia-Alania. Methods. Studies on the tasks were carried out in 2018–2020. at the experimental site of the NCRIMFA branch of the VSC of RAS in the conditions of the forest-steppe zone Republic of North Ossetia-Alania according to generally accepted methods. The soil of the experimental plot is medium-power heavy loamy leached chernozem, lined with pebbles. Results. It is established, that biological products under identical soil and weather conditions assisted different progress of plants and approach of phases of vegetation. For all variants of the experiment, the number of stems increased by 0,3–0,7 pcs., the height of the stems of potato plants – by 3,8–4,9 cm in comparison with the control. An intense increase in the mass of tops occurred when using a tank mixture (growth regulator “Regoplant” (25 ml/ha) + microfertilizer “Ultramag Combi” (0,75 l/ha)) – by 74 g/bush, or 15.5 % compared with the control variant. During the growing season, the sum of the photosynthetic potential (FP) was 1,070 thousand m2 •days/ha in the control, and on average 1198–1406 thousand m2•days/ha in the experimental variants. The greatest accumulation of dry matter was noted when using a tank mixture – 917 g/m2. The maximum pure photosynthetic productivity was observed in experimental variant IV – 6,52 g/m2•day compared to the control option. Scientific novelty. For the first time in the forest-steppe zone Republic of North Ossetia-Alania the effect of the growth regulator “Regoplant” and microfertilizer “Ultramag Kombi” on photosynthetic activity of potatoes was studied. Practical significance. The studies carried out make it possible to recommend in potato production the use of a tank mixture of an effective growth regulator “Regoplant” at a dose of 25 ml/ha and microfertilizer “Ultramag Combi” at a dose of 0,75 l/ha, as an ecologically safe and low-cost agricultural method when processing vegetative plants, providing an increase in yield and quality of tubers.


Author(s):  
O. Musienko ◽  
O. Kysterna ◽  
D. Demyanenko

The article studies in detail the disease of the mixed form of infectious diseases of honey bee brood. The characteristics of pathogens, features of diagnostics and control of this disease of honey bees are indicated. When conducting epizootic monitoring of bee diseases encountered in surveyed apiaries, it was found that a large percentage of mycosis lesions is associated with the weakening of bee families resulting from adverse weather conditions and insufficient feed base (50-68.3 %). It was further complicated by the process of varrosy invasion, which occurred in all surveyed apiaries with an invasion intensity of more than 4%. In studying the effect of weather conditions on the epizootic process, a peculiarity of the course of infectious breeding diseases in the bee family was established. It was characterized by the onset of symptoms of ascospherosis (solid chalky pieces in the cell and at the bottom of the hive) during periods of adverse weather (cold, prolonged rain). Symptoms of ascospherosis appeared not only in healthy families but also in families undergoing treatment. During the laboratory examination of dead larvae, cultures of different pathogens were isolated. A study of the contamination of cellular honey, which was selected from sick and conditionally healthy bee families, indicated that Ascosphaera apis culture was more commonly isolated and 100% contaminated. We also calculated the epizootic index of infectious diseases of bees that were found on the apiaries surveyed. Ascospherosis was found to be the longest recorded in comparison with other infectious diseases and the epizootic index was accordingly higher. And the development of European foulbroods, other types of rot and aspergillosis occurred against the background of bee ascospherosis. In a study of intestinal toxic effects of active sodium hypochlorite at concentrations of 0.7%, 0.5% and 0.25% a.d., it was found that the drug did not cause bee death within 72 hours after feeding in any group of bees. Active sodium hypochlorite effectively decontaminates test objects at a concentration of 2.5 g / l for two hours. When using cells from sick families, the concentration of 5.0 g / l was effective.


Author(s):  
Mehdi Sharafi ◽  
Zahra Poormotaseri ◽  
Jalal Karimi ◽  
Shahab Rezaeian ◽  
Seyedeh Leila Dehghani ◽  
...  

Introduction: This study aimed to determine the hotspot areas for Cutaneous Leishmaniasis (CL) in Fasa city and assess the relations between the geographical factors with CL incidence using spatial analysis. Materials and Methods: This ecological study was conducted in Fasa city, data of the CL disease such as the total number of CL cases and the population at risk from 2009 to 2014. Weather conditions' data including the means of temperature, humidity, rainfall, sunny days, rainy days, and evaporation were collected from the weather forecast centers in Fars province. The disease cases' information such as the number of disease cases was collected from all healthcare centers located in Fasa City. Ordinary Least Square (OLS) and Global Moran’s Index (GMI) were used to assess the associations of the various environmental variables with CL incidence and to map clustering of CL cases across the region. Results: The cumulative incidence of CL was 16 per 10,000 populations during a six-year period. The results showed the southern area of Fasa as a hotspot area which is considered as hyperendemic foci for CL. OLS revealed a high incidence of CL in areas with maximum temperature, mean of temperature, mean of evaporation, sunny days and wind velocity. Conclusion: A spatial disease pattern was found in the present study. Hence, substantial consideration to environmental data leads to not only suitable protection against CL but also designing a suitable measure for the prevention and control of the disease.


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