The long-term effects of applying high rates of N fertilizer to winter wheat

1989 ◽  
Vol 112 (3) ◽  
pp. 403-411 ◽  
Author(s):  
J. R. Holbrook ◽  
W. J. Ridgman
Keyword(s):  
Winter Wheat ◽  
Maximum Yield ◽  
Early Spring ◽  
Point Of View ◽  
N Fertilizer ◽  
Late Spring ◽  
Long Term Effects ◽  
Bread Making ◽  
Gross Margin

SummaryAn experiment in which all combinations of four rates of N fertilizer soon after sowing, four in early spring and nine in late spring were applied to the same plots of winter wheat for 6 years is described and the effects discussed.It was found that although the yield varied considerably from year to year the regime leading to greatest yield was fairly consistent. If the farmer had used the regime which gave the greatest average yield (0, 90, 180 kg N/ha in autumn, early spring and late spring, respectively) he would have averaged only 0·12 t/ha less than the maximum attainable each year.Application of N increased protein concentration in the grain more or less linearly but the latest application increased it most. Since the regime which gave greatest yield on average produced grain which qualified for bread-making premium from the protein point of view in all years except 1981, adopting the regime which gave maximum yield would reduce the potential maximum gross margin by only £30/ha.Analysis of the soil showed a reduction in pH down to 15 cm and of available P2O5 down to 10 cm.

scholarly journals Effects of Climate Change on Epidemics of Powdery Mildew in Winter Wheat in China

Plant Disease ◽  
2017 ◽  
Vol 101 (10) ◽  
pp. 1753-1760 ◽  
Author(s):  
Xiuli Tang ◽  
Xueren Cao ◽  
Xiangming Xu ◽  
Yuying Jiang ◽  
Yong Luo ◽  
...  
Keyword(s):  
Climate Change ◽  
Relative Humidity ◽  
Powdery Mildew ◽  
Winter Wheat ◽  
Weather Conditions ◽  
Early Spring ◽  
Long Term Effects ◽  
Temperature Changes ◽  
Disease Epidemics

Powdery mildew is a highly destructive winter wheat pathogen in China. Since the causative agent is sensitive to changing weather conditions, we analyzed climatic records from regions with previous wheat powdery mildew epidemics (1970 to 2012) and investigated the long-term effects of climate change on the percent acreage (PA) of the disease. Then, using PA and the pathogen’s temperature requirements, we constructed a multiregression model to predict changes in epidemics during the 2020s, 2050s, and 2080s under representative concentration pathways RCP2.6, RCP4.5, and RCP8.5. Mean monthly air temperature increased from 1970 to 2012, whereas hours of sunshine and relative humidity decreased (P < 0.001). Year-to-year temperature changes were negatively associated with those of PA during oversummering and late spring periods of disease epidemics, whereas positive relationships were noted for other periods, and year-to-year changes in relative humidity were correlated with PA changes in the early spring period of disease epidemics (P < 0.001). Our models also predicted that PA would increase less under RCP2.6 (14.43%) than under RCP4.5 (14.51%) by the 2020s but would be higher by the 2050s and 2080s and would increase least under RCP8.5 (14.37% by the 2020s). Powdery mildew will, thus, pose an even greater threat to China’s winter wheat production in the future.

Enhanced nitrogen management strategies for winter wheat production in the Canadian prairies

2018 ◽  
Vol 98 (3) ◽  
pp. 683-702 ◽  
Author(s):  
B.L. Beres ◽  
R.J. Graf ◽  
R.B. Irvine ◽  
J.T. O’Donovan ◽  
K.N. Harker ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Nutrient Management ◽  
Management Strategies ◽  
Maximum Yield ◽  
Nitrification Inhibitor ◽  
Early Spring ◽  
Nitrification Inhibitors ◽  
Side Band ◽  
Application Method

To address knowledge gaps around enhanced efficiency urea fertilizer efficacy for nitrogen (N) management, a study was designed to improve integrated nutrient management systems for western Canadian winter wheat producers. Three factors were included in Experiment 1: (i) urea type [urea, urea + urease inhibitor—Agrotain®; urea + urease and nitrification inhibitor—SuperU®, polymer-coated urea—Environmentally Smart Nitrogen® (ESN®), and urea ammonium nitrate (UAN)], (ii) application method (side-band vs. spring-broadcast vs. 50% side-band: 50% spring-broadcast), and (iii) cultivar (AC Radiant hard red winter wheat vs. CDC Ptarmigan soft white winter wheat). The Agrotain® and CDC Ptarmigan treatments were removed in Experiment 2 to allow for additional application methods: (i) fall side-band, (ii) 50% side-band — 50% late fall broadcast, (iii) 50% side-band — 50% early spring broadcast, (iv) 50% side-band — 50% mid-spring broadcast, and (v) 50% side-band — 50% late spring broadcast. CDC Ptarmigan produced superior grain yield and N utilization over AC Radiant. Grain yield and protein content were influenced by N form and application method. Split applications of N usually provided the maximum yield and protein, particularly with Agrotain® or SuperU®. An exception to the poor fall-application results was the SuperU® treatments, which produced similar yield to the highest-yielding treatments. The results suggest that split applications of N might be most efficient for yield and protein optimization when combined with an enhanced efficiency urea product, particularly with urease or urease + nitrification inhibitors, and if the majority of N is applied in spring.

Long-Term Effects of Tillage, Nitrogen, and Rainfall on Winter Wheat Yields in the Pacific Northwest

2003 ◽  
Vol 95 (4) ◽  
pp. 828-835 ◽  
Author(s):  
K. M. Camara ◽  
W. A. Payne ◽  
P. E. Rasmussen
Keyword(s):  
Winter Wheat ◽  
Pacific Northwest ◽  
Long Term Effects ◽  
The Pacific

scholarly journals The effects of cropping sequence, fertilization and straw management on the yield stability of winter wheat (1986–2017) in the Broadbalk Wheat Experiment, Rothamsted, UK

2020 ◽  
Vol 158 (1-2) ◽  
pp. 65-79
Author(s):  
J. Macholdt ◽  
H.-P. Piepho ◽  
B. Honermeier ◽  
S. Perryman ◽  
A. Macdonald ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Management Practices ◽  
Wheat Yield ◽  
Organic Manure ◽  
Yield Stability ◽  
N Fertilizer ◽  
Mineral N ◽  
Straw Management ◽  
Yield Risk

AbstractThe development of resilient cropping systems with high yield stability is becoming increasingly important due to future climatic and agronomic challenges. Consequently, it is essential to compare the effects of different agronomic management practices, such as cropping sequences and nutrient supply, on the stability of crop yields. Long-term experiments are a valuable resource for investigating these effects, as they provide enough time to accurately estimate stability parameters. The objective of the current study was to compare the effects of different cropping sequencing (#1: continuous v. rotational), fertilization (#2: mineral v. organic) and straw management techniques (in the case of continuous wheat; #3: removal v. incorporation) on the yield stability of winter wheat; yield risk (the probability of yield falling below a threshold yield level) and inter-annual yield variability were used as stability indicators of the effects. Long-term yield data from the Broadbalk Wheat Experiment (Rothamsted, UK) were analysed using a mixed model. Overall, the results showed that rotational cropping combined with sufficient mineral N fertilizer, with or without organic manure, ensured stable wheat yields while reducing yield risk. In contrast, higher yield risks and inter-annual yield variabilities were found in continuous wheat sections with less mineral N fertilizer or with organic manure only.

SHORT- AND LONG-TERM EFFECTS OF THE 9/11 EVENT: THE INTERNATIONAL EVIDENCE

2005 ◽  
Vol 08 (07) ◽  
pp. 947-958 ◽  
Author(s):  
VINCENT RICHMAN ◽  
MICHAEL R. SANTOS ◽  
JOHN T. BARKOULAS
Keyword(s):  
Stock Market ◽  
Capital Markets ◽  
Systematic Risk ◽  
Point Of View ◽  
Long Term Effects ◽  
Market Reactions ◽  
Theoretic Point ◽  
Short And Long Term ◽  
Stock Market Reactions

This paper analyzes the short- and long-term effects of the September 11, 2001 terrorist attacks on a comprehensive sample of stock market indices from 33 industrial and emerging economies. From a finance-theoretic point of view, we employ the international capital asset pricing model (ICAPM) to analyze the incidence of the 9/11 event. Consistent with expectations, we document statistically negative short-term stock market reactions to the 9/11 event for 28 countries. More importantly, we find increases in the level of systematic risk for 10 stock markets which attest to the presence of negative permanent effects emanating for the 9/11 event. However, a great many capital markets (including the US, Canada, Japan, China, Russia, and the largest European economies) did not experience statistically significant increases in systematic risk in the post-9/11 period. The decisiveness of the evidence clearly points in the direction of resilience and flexibility of the world capital markets.

Long-Term Effects of Diet on the Biology of the Lake Trout and the Fishery in Lake Opeongo, Ontario

1970 ◽  
Vol 27 (1) ◽  
pp. 125-146 ◽  
Author(s):  
N. V. Martin
Keyword(s):  
Lake Trout ◽  
Feeding Activity ◽  
Salvelinus Namaycush ◽  
Point Of View ◽  
Average Weight ◽  
Coregonus Clupeaformis ◽  
Long Term Effects ◽  
Food Content ◽  
Coregonus Artedii

From 1936 to 1965 food content was examined in 17,171 Lake Opeongo lake trout (Salvelinus namaycush). The diet is analysed from the point of view of frequency of occurrence of foods, their weight, feeding activity of trout, size of trout and size of food, and seasonal and annual changes in food habits.In the late 1940's and early 1950's perch, Perca flavescens, largely disappeared from the diet. The lake trout initially turned to lake whitefish, Coregonus clupeaformis, and then to the cisco, Coregonus artedii, introduced into Lake Opeongo in 1948.As a result of these dietary changes lake trout are now heavier and rate of growth has improved. Age and size at maturity is later and there are fewer infertile fish. Egg counts, egg size, and ovary weights are now greater, particularly in the medium-sized lake trout.In the fishery the average weight of individual trout taken has almost doubled. About 25% more of the immature stock is exploited by the recent fishery. The harvest and catchability of lake trout has remained generally constant on a numerical basis but show an improvement on a poundage basis in the more recent years. The possible effects of these changes on the character of the fishery are discussed.

scholarly journals Impact of soil scarification on reindeer pastures

Rangifer ◽  
1990 ◽  
Vol 10 (3) ◽  
pp. 99 ◽  
Author(s):  
Olof Eriksson ◽  
Tuomo Raunistola
Keyword(s):  
Standard Procedure ◽  
Plant Cover ◽  
Point Of View ◽  
Ground Vegetation ◽  
Long Term Effects ◽  
Surface Moisture ◽  
Positive Effects ◽  
Soil Scarification ◽  
Soil Temperatures

During recent years, soil scarification has become a standard procedure for improving seed beds after logging. Around 57 000 ha were treated, primarily through harrowing and ploughing, in the counties of V&acirc;sterbotten and Norbotten during 1985. The positive effects of scarification, from a forestry point of view, are improved access to plant nutrients, raised soil temperatures and reduces surface moisture. The aim of the present study was to describe long-term changes in the ground vegetation following scarification. Harrowing affects 45-55% of the plant cover while ploughing affects 65-90%. 10 years after ploughing and harrowing about 20% of the surface is still without vegetation. Real long-term effects remain in dispute. It has been claimed that ploughing, at least, may lead to irreversible changes.

Mikroökonometrische Evaluation der ökonomischen Wirkungen betrieblicher Mitbestimmung - Möglichkeiten und Grenzen des Matching-Ansatzes / Microeconometric Evaluation of Economic Effects of Workers Participation - Options und Limits of the Matching Approach

2006 ◽  
Vol 226 (5) ◽  
Author(s):  
Birgit Schultz
Keyword(s):  
Point Of View ◽  
Economic Effects ◽  
Small Samples ◽  
Long Term Effects ◽  
Works Councils ◽  
East German ◽  
Iab Establishment Panel ◽  
Microeconometric Evaluation ◽  
Short Time

SummaryThe evaluation of economic effects of workers participation is not simple from the methodical point of view because of specific characteristics of establishments with works councils. Especially recent studies show contradictory results. In this study problems are pointed out, discussed, and options for solution are presented on the example of workers participation in East German establishments of industry and construction by the IAB-Establishment Panel.An optimal matching-algorithm which supplies good matching-results for small samples to assign ‘statistical establishment-twins’ is applied. But by reason of very short primarily spells it can only calculate short time effects. Therefore, the matching method is additionally used to construct longer observation periods. By this new application establishments with recently founded works councils are matched with so called ‘proxy establishments’ with existing works councils. As a result short observation periods are prolonged and information about long-term effects can be given.The effects on productivity, profitability and qualification level of employees show neither in short-term nor in long-term a significant impact on workers’ participation.

scholarly journals Long-Term Effects of Different Nitrogen Levels on Growth, Yield, and Quality in Sugarcane

Agronomy ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 353 ◽  
Author(s):  
Xu-Peng Zeng ◽  
Kai Zhu ◽  
Jian-Ming Lu ◽  
Yuan Jiang ◽  
Li-Tao Yang ◽  
...  
Keyword(s):  
Fertilizer Application ◽  
Sugar Yield ◽  
N Fertilizer ◽  
Cane Yield ◽  
Sugar Accumulation ◽  
Production Cycle ◽  
Long Term Effects ◽  
N Application ◽  
Yield And Quality

Nitrogen (N) plays an important role in sugarcane (Saccharum spp. hybrids) growth and development; however, long-term effects of N application levels on cane and sugar production in different sugarcane cultivars under field conditions remain unclear. In this study, we investigate the agronomic, yield, and quality traits in three sugarcane cultivars (GT11, B9, and ROC22) under different N levels (0, 150, and 300 kg/ha urea) from 2015 to 2019. Continuous four-year field experiments of plant and ratoon crops were carried out by using two-factor split-plot design. The results showed that N fertilizer application improved the tillering rate, stalk diameter, plant height, stalk weight, millable stalks/ha, cane yield, sugar yield and juice rate of cane, and the difference between N application and non-N application was significant. The cane yield, millable stalks/ha, juice rate, and juice gravity purity increased with the increase of N application, but the milled juice brix and sucrose % cane decreased with the increase of N application. The sugar yield was the highest at 150 kg/ha urea application, while the cane yield was the highest at 300 kg/ha urea application. Different N fertilizer application levels significantly regulated the activities of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) and the contents of chlorophyll and nitrate N in plant leaves, which reflected the regulation in nitrogen metabolism and alteration in dry matter production and distribution, cane yield and sugar accumulation in different sugarcane cultivars. During the four-year experiment duration, the cane yield and sugar yield generally showed ROC22 > B9 > GT11. These data suggested that 300 kg/ha urea application was suitable for the plant and first ratoon crops, and 150 kg/ha urea application was suitable for the second and third ratoon crops. Both cane and sugar yields could be the highest in a four-year production cycle under this circumstance.

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