Dynamics of nitrogen and dry-matter partitioning and accumulation in broccoli (Brassica oleracea var. italica) in relation to extractable soil inorganic nitrogen

1999 ◽  
Vol 79 (2) ◽  
pp. 277-286 ◽  
Author(s):  
P. A. Bowen ◽  
B. J. Zebarth ◽  
P. M. A. Toivonen

The effects of six rates of N fertilization (0, 125, 250, 375, 500 and 625 kg N ha−1) on the dynamics of N utilization relative to extractable inorganic N in the soil profile were determined for broccoli in three growing seasons. The amount of pre-existing extractable inorganic N in the soil was lowest for the spring planting, followed by the early-summer then late-summer plantings. During the first 2 wk after transplanting, plant dry-matter (DM) and N accumulation rates were low, and because of the mineralization of soil organic N the extractable soil inorganic N increased over that added as fertilizer, especially in the top 30 cm. From 4 wk after transplanting until harvest, DM and N accumulation in the plants was rapid and corresponded to a rapid depletion of extractable inorganic N from the soil. At high N-fertilization rates, leaf and stem DM and N accumulations at harvest were similar among the three plantings. However, the rates of accumulation in the two summer plantings were higher before and lower after inflorescence initiation than those in the spring planting. Under N treatments of 0 and 125 kg ha−1, total N in leaf tissue and the rate of leaf DM accumulation decreased while inflorescences developed. There was little extractable inorganic soil-N during inflorescence development in plots receiving no N fertilizer, yet inflorescence dry weights and N contents were ≥50 and ≥30%, respectively, of the maxima achieved with N fertilization. These results indicate that substantial N is translocated from leaves to support broccoli inflorescence growth under conditions of low soil-N availability. Key words: N translocation, N fertilizer

1997 ◽  
Vol 128 (4) ◽  
pp. 415-424 ◽  
Author(s):  
C. J. PILBEAM ◽  
A.M. McNEILL ◽  
H. C. HARRIS ◽  
R. S. SWIFT

15N-labelled fertilizer was applied at different rates (0, 30, 60, 90 kg N ha−1) and in different forms (urea or ammonium sulphate) to wheat grown in Syria in three seasons (1991/92, 1992/93 and 1994/95).Recovery of 15N-labelled fertilizer in the above-ground crop at harvest was low (8–22%), with the amount of 15N-labelled fertilizer recovered in the crop increasing as the rate of application increased. Fertilizer application caused a significant increase in the amount of unlabelled soil N in the crop, suggesting that the application of N fertilizer caused a ‘real’ added nitrogen interaction. Recovery of 15N-labelled fertilizer in the crop was unaffected by the form of the fertilizer.On average 31% (14–54%) of the 15N-labelled fertilizer remained in the soil at harvest, mostly in the 0–20 cm layer. At the lowest application rate (30 kg N ha−1) most of the residual fertilizer was as organic N, but at the higher application rates (60 and 90 kg N ha−1), a greater proportion of the 15N-labelled fertilizer was recovered as inorganic N, presumably as the result of top-dressing N in dry conditions in the spring. The amount of 15N-labelled fertilizer remaining in the soil increased as the fertilizer rate increased, but was unaffected by the form of fertilizer applied.Losses of 15N-labelled fertilizer were large (>35%), probably caused by gaseous losses, either through volatilization of N from the calcareous soil, or through denitrification from wet soils rich in organic residues.N fertilization strategies in the West Asia/North Africa (WANA) region should take note of the low recovery of N fertilizer by the crop in the season of application, and the resultant large quantities of residual fertilizer.


2004 ◽  
Vol 84 (3) ◽  
pp. 845-854 ◽  
Author(s):  
B. J. Zebarth ◽  
Y. Leclerc ◽  
G. Moreau

This study evaluated rate and timing of N fertilization effects on the N use efficiency characteristics of rain-fed Russet Burbank potato. Trials conducted in 1999–2001 included different rates of fertili zer N (0–160 kg N ha-1 in 1999 and 0–200 kg N ha-1 in 2000 and 2001) applied either at planting according to normal grower practice, or at hilling, the latest time that granular fertilizer can practically be applied. Whole-plant dry matter and N accumulation were determined at topkill. Soil inorganic N content was measured to 30-cm depth at planting and at tuber harvest. Soil N supply (plant N accumulation plus soil inorganic N content at harvest with no fertilizer N applied) varied from 77 to 146 kg N ha-1 depending on the year. Crop N supply (soil N supply plus fertilizer N applied) was a better predictor of plant N accumulation than fertilizer N rate, and was used to remove the confounding effect of variation in soil N supply when making among-year comparisons for N use efficiency characteristics. Nitrogen uptake efficiency (NUpE; plant N accumulation/crop N supply) decreased with increasing rates of N applied at hilling N rate in 1999, which was a dry year, but was not influenced by at-hilling N rate in 2000 and 2001, or by at-planting N rate in any year. Nitrogen use efficiency (NUE; dry matter accumulation/crop N supply) and N utilization efficiency (NUtE; dry matter accumulation/plant N accumulation) decreased curvilinearly with increasing crop N supply in each year. Similar relationships between NUE and crop N supply, and between NUtE and plant N accumulation, among the 3 yr of the study suggest that these relationships are largely independent of seasonal climatic variation, and are primarily genetically controlled. Timing of N fertilization had no effect on any N use efficiency parameter, with the exception of reduced NUpE associated with split N application in 1999. This suggests that under rain-fed potato production in Atlantic Canada, timing of N fertilization has no significant effect on N use efficiency of Russet Burbank potato in years of adequate soil moisture, but NUpE may be decreased by split application of N in dry years. Key words: Solanum tuberosum, soil inorganic N, apparent fertilizer N recovery


2004 ◽  
Vol 84 (4) ◽  
pp. 421-430 ◽  
Author(s):  
Y. K. Soon ◽  
M. A. Arshad

A field study was conducted to determine the effects and interactions of crop sequence, tillage and residue management on labile N pools and their availability because such information is sparse. Experimental treatments were no-till (NT) vs. conventional tillage (CT), and removal vs. retention of straw, imposed on a barley (Hordeum vulgare L.)-canola (Brassica rapa L.)-field pea (Pisum sativum L.) rotation. 15N-labelling was used to quantify N uptake from straw, below-ground N (BGN), and fertilizer N. Straw retention increased soil microbial biomass N (MBN) in 2 of 3 yr at the four-leaf growth stage of barley, consistent with observed decreases in extractable soil inorganic N at seeding. However, crop yield and N uptake at maturity were not different between straw treatments. No tillage increased soil MBN, crop yield and N uptake compared to CT, but had no effect on extractable soil inorganic N. The greater availability of N under NT was probably related to soil moisture conservation. Tillage effects on soil and plant N were mostly independent of straw treatment. Straw and tillage treatments did not influence the uptake of N from its various sources. However, barley following pea (legume/non-legume sequence) derived a greater proportion of its N from BGN (13 to 23% or 9 to 23 kg N ha-1) than canola following barley (nonlegumes) (6 to 16% or 3 to 9 kg N ha-1). Fertilizer N constituted 8 to 11% of barley N uptake and 23 to 32% of canola N uptake. Straw N contributed only 1 to 3% of plant N uptake. This study showed the dominant influence of tillage on N availability, and of the preceding crop or cropping sequence on N uptake partitioning among available N sources. Key words: Crop residue, crop sequence, labile nitrogen, nitrogen uptake, pea, tillage


2000 ◽  
Vol 80 (4) ◽  
pp. 849-860 ◽  
Author(s):  
D. M. Dean ◽  
B. J. Zebarth ◽  
C. G. Kowalenko ◽  
J. W. Paul ◽  
K. Chipperfield

This study examined the effects of solid poultry layer manure addition on soil N processes and on dry matter and N accumulation in red raspberry (Rubus idaeus L.). In trials conducted in two years, approximately 50% of the 400 kg total N ha−1 applied as manure was recovered as soil inorganic N 1 mo after manure application when manure was incorporated within 4 h of application. Three trials were conducted in two commercial raspberry fields: one with no history of manure use and one other with a history of heavy annual applications of poultry manure. Treatments included 55 kg N ha−1 as NH4NO3, 100 or 200 kg total N ha−1 as manure, and a control that received no manure or fertilizer N. Soil inorganic N to 60 cm depth was measured throughout the growing season. Berry yield was estimated, and dry matter and N accumulation was determined in floricanes at first berry ripening and in primocanes at the end of the growing season. Few significant effects of N fertilization were measured for any crop yield, growth or N accumulation parameter. This was attributed to the large (>150 kg N ha−1) supply of N to the crop in the unamended soil, primarily from soil N mineralization. Dry matter accumulation in the fruiting clusters was strongly correlated to estimated berry yield, and may provide a simple means for assessing relative yield within experiments. Soil nitrate measured in August after berry harvest may serve as a "report card" to assess N management in the current growing season, to refine fertilizer N management for subsequent growing seasons, and as an index of the risk of nitrate leaching over the following fall and winter in south coastal British Columbia. Key words: Nitrogen mineralization, nitrate leaching, manure N availability, Rubus idaeus


1988 ◽  
Vol 28 (1) ◽  
pp. 99 ◽  
Author(s):  
MJ Blumenthal ◽  
VP Quach ◽  
PGE Searle

The effect of soybean population density on soybean yield, nitrogen accumulation and residual nitrogen was examined at Camden, N.S.W. (34�S.). In the first experiment, treatments were soybeans (cv. Ransom) at 50, 100, 200 and 400 x 103 plants ha-1; maize (cv. XL66); and a weed-free fallow. Total dry matter yields of tops and grain yields were highest at 200x 103 plants ha-1 (6214 and 3720 kg ha-1, respectively). The yield component most affected by population density was number of branches per plant, with values decreasing with increasing population density. The proportion of unfilled pods was highest at the highest population density. Total nitrogen (N) accumulation in the tops and in the grain was also at a maximum at 200x 103 plants ha-1. The rate of dry matter accumulation declined during pod filling at all population densities. N accumulation continued at high rates throughout the growing season except in the 400x 103 plants ha-1 population. There was a trend for residual dry matter and N in residues to increase with increasing population density. After grain and forage harvest of the first experiment, a crop of wheat (cv. Kite) was sown over the whole area to determine residual N available at anthesis and at maturity (experiment 2). The values of N accumulation in the wheat at maturity were 24 kg N ha-l for the maize treatment, 40-60 kg N ha-l for the soybean treatments and 69 kg N ha-1 for the fallow treatment. Grain yield and grain N followed the pattern of dry matter production and N accumulation at final harvest. The data suggest that soybean depletes soil N to a lesser extent than does maize. For the soybean treatments, there was a trend of increasing residual N at the 3 highest population densities (40-60 kg N ha-1). This was probably a result of an increase in N in leaf fall and in decaying tops and roots at the highest population density. The high value (57 kg N ha-l) at the lowest population density may be due to soybean plants at this density not using as much soil N as the other soybean treatments. No benefit in residual N was gained from planting soybeans at a density beyond the optimum for grain yield when residues were removed by forage harvesting.


1975 ◽  
Vol 55 (1) ◽  
pp. 29-34 ◽  
Author(s):  
K. A. MACMILLAN ◽  
T. W. SCOTT ◽  
T. W. BATEMAN

The response of corn (Zea mays L.) to manure that had been treated to minimize odor was investigated in a greenhouse trial with two silt loam soils of pH 4.2 and 7.1. Pretreatment of manure resulted in sources initially high in organic N and NH4+, but low in NO3−. One pretreatment gave high initial NO2− concentrations. In soil at pH 4.2, NH4+ was the major N source utilized by corn grown to 36 days, and dry matter yields were superior to those from soil at pH 7.1 where soluble NO3− was the major source of N. At pH 7.1, NO2− remained in significant quantities and decreased dry matter yields at 6 wk. Soil inorganic N concentrations varied between soils and was attributed to soil pH differences. Rate of NO2− disappearance decreased with increase in soil pH, and NH4+ accumulation increased with decrease in soil pH, whereas NO3+ production was favored by neutral pH conditions. Some NO3− production was observed in pH 4.2 soil after 36 days' incubation


Akta Agrosia ◽  
2020 ◽  
Vol 22 (2) ◽  
pp. 84-94
Author(s):  
Marwanto Marwanto ◽  
Shinta Puspita Wati ◽  
Atra Romeida ◽  
Merakati Handajaningsih ◽  
Teguh Adiprasetyo ◽  
...  

ABSTRACTFinding the appropriate method of fertilizer application to simultaneously enhance farm productivity and ensure ecosystem sustainability has been receiving a lot of attention. A field experiment was carried in the Research Plot Agriculture Faculty Bengkulu University Campus Indonesia in 2017. The purpose of this study was (1) to assess the significant effects of inorganic N fertilizer (IF) substitution with bio-fortified compost (BC) under equal N conditions on growth, N accumulation, and yield of sweet corn, and (2) to determine the appropriate level to which inorganic N fertilizer could be reduced and equivalently replaced by bio-fortified compost to promote sweet corn growth and yield. The treatments consisted of six different proportions of inorganic N fertilizer (IF) substitution with bio-fortified compost (BC). Each treatment was designed on the basis of equal amount of total N input from a combination of both fertilizers (138 kg N ha-1).  They were arranged in a randomized block design with 3 replications. They included (1) 100% IF plus 0% BC, (2) 75% IF plus 25% BC, (3) 50% IF plus 50% BC, (4) 25% IF plus 75%, (5) 0% IF plus 100% BC, and (6) no IF and no BC. The results showed that the increasing proportion of IF replaced by BC resulted in an increase for all variables (except for plant height) but they decreased when 100% IF substitution with 100% BC was applied. Among the partial substitution treatments, 50% IF plus 50% BC consistently produced the best growth, N accumulation, and yield increase. Treatments of 50% IF plus 50% BC and 25% IF plus 75% BC produced the highest green cob weight with husk per plot (10.74 – 10.84 kg plot-1), which was 16% to 19% higher than treatment of 100% IF plus % BC. The three partial substitution treatments produced crop yield components as good as treatment of 100% IF plus 0% BC. Treatment of 0% IF plus 100% BC reduced plant growth, N accumulation, and crop yield and its components. The appropriate level to which IF could be reduced and equivalently replaced by BC was at the range of 25% to 75%. Hence, a suitable replacement of inorganic N fertilizer with bio-fortified compost is considered a reasoned way to simultaneously increase crop yield and reduce environmental degradation.Keywords: organic fertilizer, chemical fertilizer, bio-fortification, chemical fertilizer substitution, bio-fortified compost


HortScience ◽  
2000 ◽  
Vol 35 (7) ◽  
pp. 1258-1262 ◽  
Author(s):  
Sidat Yaffa ◽  
Bharat P. Singh ◽  
Upendra M. Sainju ◽  
K.C. Reddy

Sustainable practices are needed in vegetable production to maintain yield and to reduce the potential for soil erosion and N leaching. We examined the effects of tillage [no-till (NT), chisel plowing (CP), and moldboard plowing (MP)], cover cropping [hairy vetch (Vicia villosa Roth) vs. winter weeds], N fertilization (0, 90, and 180 kg·ha-1 N), and date of sampling on tomato (Lycopersicon esculentum Mill.) yield, N uptake, and soil inorganic N in a Norfolk sandy loam in Fort Valley, Ga. for 2 years. Yield was greater with CP and MP than with NT in 1996 and was greater with 90 and 180 than with 0 kg·ha-1 N in 1996 and 1997. Similarly, aboveground tomato biomass (dry weight of stems + leaves + fruits) and N uptake were greater with CP and MP than with NT from 40 to 118 days after transplanting (DAT) in 1996; greater with hairy vetch than with winter weeds at 82 DAT in 1997; and greater with 90 or 180 than with 0 kg·ha-1 N at 97 DAT in 1996 and at 82 DAT in 1997. Soil inorganic N was greater with NT or CP than with MP at 0- to 10-cm depth at 0 and 30 DAT in 1996; greater with hairy vetch than with winter weeds at 0- to 10-cm and at 10- to 30-cm at 0 DAT in 1996 and 1997, respectively; and greater with 90 or 180 than with 0 kg·ha-1 N from 30 to 116 DAT in 1996 and 1997. Levels of soil inorganic N and tomato N uptake indicated that N release from cover crop residues was synchronized with N need by tomato, and that N fertilization should be done within 8 weeks of transplanting. Similar tomato yield, biomass, and N uptake with CP vs. MP and with 90 vs. 180 kg·ha-1 N suggests that minimum tillage, such as CP, and 90 kg·ha-1 N can better sustain tomato yield and reduce potentials for soil erosion and N leaching than can conventional tillage, such as MP, and 180 kg·ha-1 N, respectively. Because of increased vegetative cover in the winter, followed by increased mulch and soil N in the summer, hairy vetch can reduce the potential for soil erosion and the amount of N fertilization required for tomato better than can winter weeds.


1996 ◽  
Vol 44 (3) ◽  
pp. 227-239
Author(s):  
H. Biemond ◽  
J. Vos ◽  
P.C. Struik

Four greenhouse and 2 field experiments (the latter on a sandy soil) were carried out with different amounts and dates of N application to analyse the dynamics of dry matter and N accumulation in spinach (cv. Trias). Frequent measurements were carried out on dry matter and N accumulation in leaf blades, petioles and stems. The total accumulation of dry matter and N differed largely among and within experiments. Increasing N application increased yield of dry matter and N accumulation, whereas splitting N applications had much smaller effects. However, the partitioning of dry matter and N proved insensitive to N treatments. Harvest indices for dry matter (about 0.67) or N (about 0.74) of crops at a marketable stage were fairly constant over treatments and experiments. Increasing or splitting the N application affected N accumulation more than dry matter production, resulting in large effects on N concentrations. The lack of variation in response to N for different N regimes facilitates the development of N application techniques aimed at high yield, high quality and reduced emissions. The organic N concentration of leaf blades and petioles decreased with leaf age, although in most experiments this decrease was smaller at higher leaf numbers. The nitrate-N concentration decreased with increasing leaf number at any sampling date; it was higher when N was abundant. High yields in autumn crops were associated with high nitrate concentrations but also with potentially high losses of N.


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