Irrigation frequency and nitrogen fertilizers modify cotton yield at Emerald, central Queensland

1993 ◽  
Vol 44 (6) ◽  
pp. 1389 ◽  
Author(s):  
SE Ockerby ◽  
DJ Lyons ◽  
GD Keefer ◽  
FPC Blamey ◽  
DF Yule

Four irrigation frequencies and six nitrogen (N) fertilizer rates (0-300 kg ha-1) were applied to cotton (Gossypium hirsutum L.) grown on three Vertisols in the Emerald Irrigation Area, central Queensland. The purpose was to describe lint production responses to the plant available water before irrigation and N fertilizer, in terms of the crop N content and the efficiency of crop N use for lint production. Lint yield was greatest when the plant available water before irrigation was 50-80010 of the plant available water capacity (PAWC) of each soil. The rate of N fertilizer for maximum yield varied with plant available water and soil type. Plant available water before irrigation >60% and <37% PAWC, and rain after irrigation reduced the crop N content at the time of maximum leaf area index. Relative yield generally responded to 130 kg crop N ha-', although the range from 101 to 141 kg crop N ha-1 reflected differences in the maximum yield of each treatment. If the crop N was <130 kg ha-1, yield was mostly determined by the crop N content, whereas if the crop N content was >130 kg ha-1, yield and the efficiency of crop N use for lint production was determined by the plant available water before irrigation and soil type. Nitrogen fertilizer strategies to achieve the maximum yield of cotton (var. Deltapine 61) should focus on obtaining 130 kg crop N ha-1. This crop N content produced maximum yields for a range of plant available water contents before irrigation, and for three soil types.

1978 ◽  
Vol 90 (3) ◽  
pp. 509-516 ◽  
Author(s):  
A. Penny ◽  
F. V. Widdowson ◽  
J. F. Jenkyn

SummaryAn experiment at Saxmundham, Suffolk, during 1974–6, tested late sprays of a liquid N-fertilizer (ammonium nitrate/urea) supplying 50 kg N/ha, and a broad spectrum fungicide (benomyl and maneb with mancozeb) on winter wheat given, 0, 50, 100 or 150 kg N/ha as ‘Nitro-Chalk’ (ammonium nitrate/calcium carbonate) in springMildew (Erysiphe graminisf. sp. tritici) was most severe in 1974. It was increased by N and decreased by the fungicide in both 1974 and 1975, but was negligible in 1976. Septoria (S. nodorum) was very slight in 1974 and none was observed in 1976. It was much more severe in 1975, but was unaffected by the fungicide perhaps because this was applied too late.Yield and N content, number of ears and leaf area index were determined during summer on samples taken from all plots given 100 or 150 kg N/ha in spring; each was larger with 150 than with 100 kg N/ha. The effects of the liquid N-fertilizer on yield and N content varied, but leaf area index was consistently increased. None was affected consistently by the fungicide.Yields, percentages of N in, and amounts of N removed by grain and straw were greatly and consistently increased by each increment of ‘Nitro-Chalk’. Yields of grain were increased (average, 9%) by the liquid fertilizer in 1974 and 1975, and most where most ‘Nitro-Chalk’ had been given, but not in 1976 when the wheat ripened in July; however, both the percentage of N in and the amount of N removed by the grain were increased by the liquid fertilizer each year. The fungicide increased the response to the liquid N-fertilizer in 1974, but not in 1975 when Septoria was not controlled, nor in 1976 when leaf diseases were virtually absent.The weight of 1000 grains was increased by each increment of ‘Nitro-Chalk’ in 1975 but only by the first one (50 kg N/ha) in 1974 and 1976; it was very slightly increased by the liquid fertilizer and by fungicide each year.


2004 ◽  
Vol 84 (1) ◽  
pp. 129-142 ◽  
Author(s):  
S. Bittman ◽  
B. J. Zebarth ◽  
C. G. Kowalenko ◽  
D. E. Hunt

This study compared the response of harvests taken in May, June, August and September-October in terms of crop responses (yield, N uptake, and concentrations of crude protein and nitrate) to N fertilizer and residual soil nitrate and ammonium. Three trials were conducted in south coastal British Columbia in 1990–1992 to evaluate the response of an established sward of orchardgrass (Dactylis glomerata L.) to a range of N fertilizer rates. Both yields and daily crop growth rates were highest in cut 1, lowest in cut 4 and intermediate in cuts 2 and 3. For all four cuts, 95 and 90% of maximum yield was attained at about 136 and 82 kg ha-1 of applied N, respectively. Crop N supply from non-fertilizer sources ranged from 36 to 90 kg N ha-1, of which about 52% was attributed to nitrate present in the soil prior to growth and about 48% was N released from the soil, translocated from roots or deposited from the atmosphere. At 95% of maximum yield, crude protein concentrations ranged from 147 g kg-1 in the higher yielding cut 1 to 189 g kg-1 in cuts 2 and 4, while at 90% of maximum yield concentrations were 10 g kg-1 lower in each cut. Plant nitrate concentrations were close to levels that are toxic to cattle for the 95% target yield, but relatively safe at the 90% yield. The crop removed about 50 kg ha-1 more N when fertilized for 95% of maximum yield than for 90%, which translates to over 300 kg ha-1 more crude protein. High relative yield leaves behind more soil nitrate after harvest. The results suggest that the first cut should be managed for 95% of maximum yield with about 130 kg N ha-1. Cuts 2 and 3 should be managed for 90% of maximum yield, to avoid high plant nitrate concentrations, with 100–110 kg N ha-1. Cut 4 should be given no more than 50 kg N ha-1 for less than 90% of maximum yield because of the risk of residual soil nitrates. This study shows for the first time the benefits and disadvantages of applying N at different rates for each harvest over the growing season. Key words: Plant nitrate, nitrogen use efficiency, nitrogen recovery, Dactylis glomerata, relative yield, maximum economic yield


Agriculture ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 500
Author(s):  
Ke Zhang ◽  
Xue Wang ◽  
Xiaoling Wang ◽  
Syed Tahir Ata-Ul-Karim ◽  
Yongchao Tian ◽  
...  

Accurately summarizing Nitrogen (N) content as a prelude to optimal N fertilizer application is complicated during the vegetative growth period of all the crop species studied. The critical nitrogen (N) concentration (Nc) dilution curve is a stable diagnostic indicator, which performs plant critical N concentration trends as crop grows. This study developed efficient technologies for different organ-based (plant dry matters (PDM), leaf DM (LDM), stem DM (SDM), and leaf area index (LAI)) estimation of Nc curves to enrich the practical applications of precision N management strategies. Four winter wheat cultivars were planted with 10 different N treatments in Jiangsu province of eastern China. Results showed the SDM-based curve had a better performance than the PDM-based curve in N nutrition index (NNI) estimation, accumulated N deficit (AND) calculation, and N requirement (NR) determination. The regression coefficients ‘a’ and ‘b’ varied among the four critical N dilution models: Nc = 3.61 × LDM–0.19, R2 = 0.77; Nc = 2.50 × SDM–0.44, R2 = 0.89; Nc = 4.16 × PDM–0.41, R2 = 0.87; and Nc = 3.82 × LAI–0.36, R2 = 0.81. In later growth periods, the SDM-based curve was found to be a feasible indicator for calculating NNI, AND, and NR, relative to curves based on the other indicators. Meanwhile, the lower LAI-based curve coefficient variation values stated that leaf-related indicators were also a good choice for developing the N curve with high efficiency as compared to other biomass-based approaches. The SDM-based curve was the more reliable predictor of relative yield because of its low relative root mean square error in most of the growth stages. The curves developed in this study will provide diverse choices of indicators for establishing an integrated procedure of diagnosing wheat N status, and improving the accuracy and efficiency of wheat N fertilizer management.


Weed Science ◽  
2004 ◽  
Vol 52 (6) ◽  
pp. 1039-1049 ◽  
Author(s):  
R. Jason Cathcart ◽  
Clarence J. Swanton

Agronomic research on the effects of nitrogen fertilizer and weed control in corn has focused primarily on maintaining or increasing yield. Few studies have examined the effect of nitrogen (N) fertilizer rate or weed competition (or both) on whole plant growth and development. The objectives of this research were to determine how N influences the growth and development of corn and to explore how green foxtail density affects this relationship. Field experiments were conducted on a sandy low organic matter soil from 1999 to 2001. The experiment was designed as a factorial with N rate ranging from 0 to 200 kg N ha−1and targeted green foxtail density ranging from 0 to 300 plants m−2. Under weed-free conditions, a higher rate of N fertilizer increased corn leaf and grain N content, leaf area index (LAI), plant height, and aboveground dry matter (DM) production, including kernel weight. However, in the presence of green foxtail, corn leaf N content, LAI, growth rate, plant height, and aboveground DM were reduced at each N level. Despite having significant main effects, there was no interaction between N rate and green foxtail density. Results indicate that in corn grown on a coarse-textured soil with low organic matter, the additional stress brought about by the presence of green foxtail exacerbated the effect of low N rates on corn growth and development. More intensive weed management may be required in corn if N fertilizer rates are reduced.


HortScience ◽  
2005 ◽  
Vol 40 (1) ◽  
pp. 214-217 ◽  
Author(s):  
S.B. Phillips ◽  
J.G. Warren ◽  
G.L. Mullins

Previous work suggests that `Beauregard' sweetpotato [Ipomoea batatas (L.) Lam.] has a much lower N requirement than other common cultivars. Over the past 10 years, `Beauregard' has become the premier sweetpotato cultivar grown in Virginia; however, N fertilizer recommendations have not been reassessed to consider the potentially lower N requirement of `Beauregard'. The objectives of this study were to evaluate the effects of N rate and application timing on root yield, quality, and N use efficiency for `Beauregard' sweetpotato production in Virginia. A field study was conducted each year from 2000 to 2002 at the Eastern Shore Agricultural Research and Extension Center, Painter, Va. Nitrogen fertilizer was applied at rates of 28, 56, and 84 kg·ha-1 either before transplanting, 2 to 3 weeks after transplanting (WAT), or 4 to 5 WAT. A check treatment that received no N fertilizer was also included. Optimum N rates varied annually; under normal precipitation, root yield was greatest at the 28-kg·ha-1 rate, while 56 kg·ha-1 was required for maximum yield in wet conditions. Of note is that this range of rates is considerably lower than the current N recommendation for Virginia sweetpotato production (56 to 84 kg·ha-1). Delaying N application until 2 to 3 WAT further increased marketable root yield compared with applying N before transplanting or 4 to 5 WAT. Crude protein and N uptake increased with increasing N rate up to 84 kg·ha-1; however, N use efficiency was highest (67%) when 28 kg·ha-1 was applied 2 to 3 WAT.


2011 ◽  
Vol 91 (2) ◽  
pp. 199-210 ◽  
Author(s):  
Mingbin Huang ◽  
S. Lee Barbour ◽  
Amin Elshorbagy ◽  
Julie Zettl ◽  
Bing Cheng Si

Huang, M., Barbour, S. L., Elshorbagy, A., Zettl, J. D. and Si, B. C. 2011. Water availability and forest growth in coarse-textured soils. Can. J. Soil Sci. 91: 199–210. A method of evaluating the influence of soil layering and climatic variability on plant available water for forest growth is presented. This method enables species-specific levels of maximum sustainable plant transpiration to be evaluated. A calibrated HYDRUS-1D model was used with a 60-yr meteorological record to simulate actual evapotransipration (ETa) of dominant tree species with different values of leaf area index (LAI) for three sites in northern Alberta. A probability distribution of ETa was developed for each case. The relationships between LAI, plant above-ground primary production (ANPP), and ETa were used to estimate the minimum water demand to support plant growth at specific sites. The developed frequency curves of ETa and the minimum water demand can be used to determine the maximum sustainable LAI and the risk associated with revegetating a particular site with a dominant tree species. The effect of different tree species on the minimum water demand and the maximum sustainable LAI was also illustrated. The results indicated that layering of coarse-textured soils can provide more plant available water and support a higher maximum sustainable LAI than homogeneous soils of a similar texture.


2018 ◽  
Vol 98 (4) ◽  
pp. 815-829 ◽  
Author(s):  
L.L. Van Eerd ◽  
J.J.D. Turnbull ◽  
C.J. Bakker ◽  
R.J. Vyn ◽  
A.W. McKeown ◽  
...  

Optimizing N fertilizer applications involves maximizing N use efficiency (NUE) while minimizing losses but depends on complex interactions of crop, soil, weather, and management practices. One approach may be to use controlled-release fertilizer that synchronizes N availability with plant demand. A field experiment at two Ontario locations from 2007 to 2009 compared split-applied ammonium nitrate (ANs) to preplant-applied poly-coated urea (PCU) and soluble N at a ratio of 75:25 at five N rates on late-season storage cabbage (Brassica oleracea L. var. capitata). Maximum yield and profit margins were obtained at an average of 286 and >300 kg N ha−1, but few differences among sources were observed. Compared with ANs, PCU did not affect plant N content, nor did PCU reduce soil nitrate or NUE, which indicates little differences in risk of environmental N losses between N sources. Dissolution from mesh bags indicated 5%–25% of various PCU formulations remained by harvest but 5%–10% remained by spring, which suggests conservation over the winter, a need to synchronize N release with crop uptake, and partially explains the lack of treatment differences. From agronomic, economic, and environmental perspectives, the tested PCU treatments for cabbage production in a humid, temperate climate were equivalent to the standard practice.


Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-13 ◽  
Author(s):  
Xiukang Wang ◽  
Yingying Xing

The purpose of this study is to investigate the interactions between irrigation and fertilizer treatments on soilNO3--N content and vertical distribution under drip fertigation in greenhouse tomatoes. Randomized block design with three replications and the treatments consisting of three levels of irrigation and three levels of N fertilizer were used. Three irrigation levels were W1 (100%  ET0), W2 (75%  ET0), and W3 (50%  ET0) and fertilizer levels were F1 (N240–P2O5120–K2O150 kg hm−2), F2 (N180–P2O590–K2O112.5 kg hm−2), and F3 (N120–P2O560–K2O75 kg hm−2). The result demonstrates that dynamics of soilNO3--N and its response to drip fertigation and levels of N moved toward the fore soil moist, and the average soilNO3--N content with W3 treatment was 1.23 times higher than that of the W1 treatment in 0–60 cm at 43 days after transplanting. The negative correlation between N use efficiency and levels of fertilizer N and the N recovery efficiency was increased with increases of N fertilizer application. The fertilizer nitrogen rate greatly significantly influenced soilNO3--N content. Avoiding N leaching through controlled matching N fertilizer application and controlled irrigation to tomato N demand is the key to maintain crop yield and improve N use efficiency.


2001 ◽  
Vol 81 (5) ◽  
pp. 535-544 ◽  
Author(s):  
G. Bélanger ◽  
J. R. Walsh ◽  
J. E. Richards ◽  
P. H. Milburn ◽  
N. Ziadi

Nitrogen greatly affects potato ( Solanum tuberosum L.) yield, but excess N can result in environmental degradation. In this study soil nitrate (NO3-N) content was determined pre-plant to predict fertilizer N requirements of potatoes in Atlantic Canada and in mid-season to adjust N fertilization during the growing season. Soil NO3-N contents were measured to a 0.30-m depth in spring prior to planting at four on-farm sites in each of 3 yr (1995 to 1997) in the upper St. John River Valley of New Brunswick, Canada. Mid-season soil NO3-N contents at a 0–0.30 m depth were also determined (32–47 days after planting) at two sites in three N treatments in 1995 (0, 50, and 250 kg N ha-1) and in four N treatments in 1996 and 1997 (0, 50, 100, and 250 kg N ha-1). The yield response of potatoes to six rates of N fertilization (0–250 kg N ha-1) with and without supplemental irrigation was used to determine the economically optimum N application (Nop). The pre-plant spring soil NO3-N test alone could not adequately predict the N requirements of potatoes in Atlantic Canada; the Nop and relative yield were poorly correlated (0.07 < R2< 0.52) with spring soil NO3-N content. The mid-season soil NO3-N test, however, could be used to determine the need for supplemental N fertilizer; NO3-N content correlated well (0.44 < R2< 0.68) with the relative yield for total and marketable yield. We suggest a critical mid-season value of 80 mg NO3-N kg-1 soil for marketable yield, above which additional N application might not be necessary. Key Words: N fertilizer, nitrate, Nop, relative yield, Solanum tuberosum, critical value


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