LONG-RANGE EFFECTS OF INTENSIVE CULTIVATION AND MONOCULTURE ON THE QUALITY OF SOUTHERN ONTARIO SOILS

1980 ◽  
Vol 60 (3) ◽  
pp. 403-410 ◽  
Author(s):  
J. W. KETCHESON
Keyword(s):  
Significant Proportion ◽  
Total Porosity ◽  
Field Studies ◽  
Yield Reduction ◽  
Soil Productivity ◽  
Organic C ◽  
Yield Increase ◽  
C And N ◽  
Impaired Water

Ontario holds a significant proportion of the land base for Canada’s food production. Many of the soils are vulnerable to the effects of erosion and intense cropping. Laboratory and field studies indicate that monoculture systems without grass-legume forages lower organic C and N equilibrium levels. Structure and tilth, in terms of total porosity and stable aggregation, are impaired. Marked increases in land areas in monoculture, particularly corn and beans, have occurred in the last 20 yr and could lead to lower yield potentials. However, contrary to this expected trend in soil productivity, Ontario’s census records indicate a yield increase of 1.88 t/ha for nine commonly-grown crops over the 20-yr period. Fertilizer recommendations at the end of the period have decreased to approximately 60% of the amount recommended at the beginning. Deterioration of soil by wind and water erosion is a matter of concern. While average losses are estimated between 0.07 and 1.9 t/ha for different watersheds, individual field situations exceed this and may create serious problems in yield reduction and impaired water quality.

Response of LibertyLink and WideStrike Cotton to Varying Rates of Glufosinate

2015 ◽  
Vol 29 (4) ◽  
pp. 665-674 ◽  
Author(s):  
Darrin M. Dodds ◽  
Christopher L. Main ◽  
L. Thomas Barber ◽  
Charles Burmester ◽  
Guy D. Collins ◽  
...  
Keyword(s):  
North Carolina ◽  
Growth Parameters ◽  
Fiber Quality ◽  
Field Studies ◽  
Application Rate ◽  
Yield Reduction ◽  
Single Application ◽  
Application Rates ◽  
Growth Development

Field studies were conducted in Alabama, Arkansas, Georgia, Louisiana, Mississippi, North Carolina, and Tennessee during 2010 and 2011 to determine the effect of glufosinate application rate on LibertyLink and WideStrike cotton. Glufosinate was applied in a single application (three-leaf cotton) or sequential application (three-leaf followed by eight-leaf cotton) at 0.6, 1.2, 1.8, and 2.4 kg ai ha−1. Glufosinate application rate did not affect visual injury or growth parameters measured in LibertyLink cotton. No differences in LibertyLink cotton yield were observed because of glufosinate application rate; however, LibertyLink cotton treated with glufosinate yielded slightly more cotton than the nontreated check. Visual estimates of injury to WideStrike cotton increased with each increase in glufosinate application rate. However, the injury was transient, and by 28 d after the eight-leaf application, no differences in injury were observed. WideStrike cotton growth was adversely affected during the growing season following glufosinate application at rates of 1.2 kg ha−1 and greater; however, cotton height and total nodes were unaffected by glufosinate application rate at the end of the season. WideStrike cotton maturity was delayed, and yields were reduced following glufosinate application at rates of 1.2 kg ha−1 and above. Fiber quality of LibertyLink and WideStrike cotton was unaffected by glufosinate application rate. These data indicate that glufosinate may be applied to WideStrike cotton at rates of 0.6 kg ha−1 without inhibiting cotton growth, development, or yield. Given the lack of injury or yield reduction following glufosinate application to LibertyLink cotton, these cultivars possess robust resistance to glufosinate. Growers are urged to be cautious when increasing glufosinate application rates to increase control of glyphosate-resistant Palmer amaranth in WideStrike cotton. However, glufosinate application rates may be increased to maximum labeled rates when making applications to LibertyLink cotton without fear of reducing cotton growth, development, or yield.

EFFECT OF FERTILIZER ON SOIL PRODUCTIVITY IN LONG-TERM SPRING WHEAT ROTATIONS

1987 ◽  
Vol 67 (1) ◽  
pp. 165-174 ◽  
Author(s):  
H. H. JANZEN
Keyword(s):  
Organic Matter ◽  
N Fertilization ◽  
N Fertilizer ◽  
Organic N ◽  
Phosphorus Fertilization ◽  
Soil Productivity ◽  
Organic C ◽  
C And N ◽  
N Fertility

Surface soil samples taken from two long-term crop rotations at Lethbridge, Alberta were used to assess the influence of fertilizer N and P on total and mineralizable concentrations of organic C and N in a Dark Brown Chernozemic soil. Rotations sampled were continuous wheat and fallow-wheat-wheat initiated in 1912. In 1967 and 1972, N fertilizer and P fertilizer treatments, respectively, were superimposed over the rotation treatments (which had received no previous fertilizer) to produce a factorial of two N rates (0 and 45 kg N ha−1) by two P rates (0 and 20 kg P ha−1). After 18 yr of application, N fertilizers increased organic C content in both rotations by approximately 14% over that observed in soil receiving no N fertilizer. Organic N contents, similarly, were increased by 15 and 11% in the continuous wheat and fallow-wheat-wheat rotations, respectively. As well, N fertilization increased relative N mineralization potential by 22% in the continuous wheat rotation and by 44% in the fallow-wheat-wheat rotation. Phosphorus fertilization had no significant influence on either total or mineralizable C and N concentrations. Soil pH (measured in dilute CaCl2) was reduced, on average, from 7.2 to 6.9 by 18 annual N applications. These results demonstrate that N fertilization can make significant contributions to the replenishment of organic matter in soil and to the maintenance of indigenous soil N fertility. Key words: Organic matter, nitrogen, carbon, mineralizable nitrogen, mineralizable carbon, pH

Effect of management of previous cereal stubble on nitrogen fertiliser requirement of wheat

1992 ◽  
Vol 32 (3) ◽  
pp. 355 ◽  
Author(s):  
MG Mason
Keyword(s):  
Grain Yield ◽  
Wheat Crop ◽  
Yield Reduction ◽  
Total N ◽  
Organic C ◽  
Yield Increase ◽  
Fallow Systems ◽  
Rate Interaction ◽  
Yield Responses ◽  
Yield Decrease

The effect of either burning stubble, or incorporating it in the soil, on the nitrogen (N) fertiliser requirement of the following wheat crop was examined over 10 years (1978-87) in a continuous wheat system at 2 sites (Wongan Hills and Nabawa), and in both continuous wheat and wheat-fallow systems at one site (Merredin). There were significant grain yield increases in response to N fertiliser in all years at Nabawa. At Wongan Hills there was no response in 1978 and 1985, a yield reduction in 1979, and a yield increase in all other years. At Merredin, there was no response in 1980, a yield decrease in 1984 and 1985, and an increase in all other years. In some years grain yield responses were small at Wongan Hills and Merredin. The only significant overall effects of stubble treatment were at Nabawa in 1978 (P<0.01) and 1985 (P<0.05). The interaction between stubble treatment and N rate was significant at Wongan Hills in 1980 and 1981 (P<0.05), and at Merredin in 1981 (P<0.001), 1983, and 1985 (both P<0.05). Response to N fertiliser was higher where the stubble was incorporated than where it was burnt. There was also a tendency for higher optimum economic rates of N fertiliser with stubble incorporated rather than burnt, but differences were not large. At Merredin, the overall yield increase with fallow was significant (P<0.001) in 1979 and 1983. The fallow x N fertiliser rate interaction was significant in all comparison years except 1987. Responses to N were greater in the non-fallow treatments. Soil organic carbon (C) levels were higher with stubble incorporation than where the stubble was burnt, and fallowing resulted in lower organic C. There was a downward trend with time, especially when fallowing was carried out. Effects on total N levels in the soil were similar to those for organic C but were less marked. The study indicates that at a level of stubble residues of 1-3 t/ha with continuous wheat in this winter rainfall environment in Western Australia, stubble treatment is unlikely to be a major factor in determining the rate of N fertiliser required for a wheat crop.

scholarly journals Long-term tillage, straw and N rate effects on quantity and quality of organic C and N in a Gray Luvisol soil

2010 ◽  
Vol 90 (1) ◽  
pp. 1-20 ◽  
Author(s):  
S. S. Malhi ◽  
M. Nyborg ◽  
T. Goddard ◽  
D. Puurveen
Keyword(s):  
Organic C ◽  
Rate Effects ◽  
C And N ◽  
Gray Luvisol

scholarly journals The influence of the combined coulter operation on the quality and yield of grain

2020 ◽  
Vol 1 (6) ◽  
pp. 72-77
Author(s):  
A.A. Kem ◽  
◽  
M.S. Chekusov ◽  
A.N. Shmidt ◽  
◽  
...  
Keyword(s):  
Spring Wheat ◽  
Weather Conditions ◽  
Field Studies ◽  
Soil Horizon ◽  
Mineral Fertilizers ◽  
Yield Increase ◽  
Yield And Quality ◽  
Starting Dose ◽  
The Difference

The article presents the results of the studies of the effect of the combined paw coulter for multi-level sowing of grain crops and the simultaneous introduction of a starting dose of mineral fertilizers on the quality and yield of grain of soft spring wheat Omskaya 36 carried out in 2019-2020. When sowing using the SKP-2.1M seeder, which was reequipped with combined coulters, where mineral fertilizers were applied below the seeds of spring wheat, the yield increase in the experiments carried out in 2019 by 14% average in comparison with the control sowing with the SKP-2.1 seeder with serial coulters, where mineral fertilizers were applied to the same soil horizon with seeds. The conducted field experiment in 2020 confirmed the previously obtained results of the coulter performance; the increase in grain when using the combined coulters on the SPK-2.1M seeder was 12.5%. The difference in grain yield happened due to the different weather conditions in 2019 and 2020. The qualitative indicators of spring soft wheat when sowing with combined openers in comparison with a serial seeder gave an average increase in protein by 7.9% and 4.7%, and the highest gluten values on the control seeder were in the range of 25.8-27.1%, and on the experi-mental SKP-2.1M seeder it was 26.1−28.5% in 2019-2020, respectively. Thus, according to the re-sults of the laboratory field studies carried out over two years, it was found that the proposed design of the combined coulter for sowing and applying mineral fertilizers below the sowing of seeds is efficient and it contributes to an increase in yield and quality of grain of soft spring wheat.

Operations Research on the Female Village-Based Family Planning Worker Program of Pakistan

1998 ◽  
Vol 18 (3) ◽  
pp. 283-305
Author(s):  
Louisiana Lush ◽  
George P. Cernada ◽  
A. K. Ubaidur Rob ◽  
Mohammed Shafiq Arif ◽  
Minhaj Ul Haque ◽  
...  
Keyword(s):  
Family Planning ◽  
Operations Research ◽  
Technical Assistance ◽  
Field Studies ◽  
Family Planning Services ◽  
Training And Supervision ◽  
The Government ◽  
And Training ◽  
Broad Program

This article presents the results of a number of operations research studies (OR) of family planning services provided by a new cadre of female village-based family planning workers in Punjab Province, Pakistan. This cadre of workers, recruited nationwide, have been trained to visit women in their villages to provide information and family planning services. The studies were conducted as part of a broad program of technical assistance to the Government of Pakistan. Surveys investigated the quality of their training as well as attitudes among clients to the new program. They found that the program is developing well but there is room for improvement, particularly in counseling and training. Additional field studies are ongoing and recommendations for change have been incorporated in training and supervision. The program is expanding on a national scale.

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