Tree growth and nutrient cycling in dense plantings of hybrid poplar and black alder

1987 ◽  
Vol 17 (6) ◽  
pp. 516-523 ◽  
Author(s):  
B. Côté ◽  
C. Camiré
Keyword(s):  
N Uptake ◽  
Hybrid Poplar ◽  
Nutrient Content ◽  
Growing Season ◽  
First Year ◽  
Biomass Growth ◽  
Soil N ◽  
Black Alder ◽  
The Third ◽  
Poplar Growth

The cycling of N, P, K, Ca, and Mg was quantified during the third growing season in plantings (33 × 33 cm) of black alder (Alnusglutinosa (L.) Gaertn.) and hybrid poplar cv. Roxbury (Populusnigra L. × Populustrichocarpa Torr and Gray). First-year nutrient uptake, tree growth, and nutrient status of poplar were also assessed. During the 1st year, height and above-ground biomass growth of poplar were positively correlated with the proportion of alder in a plot. Poplar was twice as tall as alder in a mixed treatment and produced three times the aboveground biomass of alder in mixed plantings. On an individual tree basis, 1st year soil N uptake of alder averaged 46% of poplar N uptake. First-year winter dieback of poplar in this study prevented alder from being completely shaded by the poplars. Biomass growth and N status of poplar in the 2nd year were improved in mixed culture. After 3 years, accumulation of N and P in trees increased with the proportion of alder in a plot (maxima of 219 and 21 kg ha−1, respectively), but the greatest accumulations of N derived from the soil and K, Ca, and Mg were in mixed plantings (140, 88, 69, and 22.4 kg ha−1). Except for P, soil nutrient uptake during the third growing season was highest in plots with one alder for two poplars (maxima of 108, 9.1, 50, 60, and 19 kg ha−1 for N, P, K, Ca, and Mg). Throughfall nutrient content was not affected by species mixture. Except for Ca, nutrient content of total leaf litter increased with the proportion of alder (maxima of 80, 3.1, 13, 35, and 6.9 kg ha−1 for N, P, K, Ca, and Mg). After 3 years, no accretion of total N was detected in the soil, but exchangeable K increased 93% in the top 5 cm. Because stimulatory effect of interplanted alder on poplar growth decreased with time, reduced competition for soil N and light from the smaller alder during the first growing season were considered the most important factors in increasing individual poplar growth in our plantation.

scholarly journals Development of an Online Tool for Tracking Soil Nitrogen to Improve the Environmental Performance of Maize Production

2021 ◽  
Vol 13 (10) ◽  
pp. 5649
Author(s):  
Giovani Preza-Fontes ◽  
Junming Wang ◽  
Muhammad Umar ◽  
Meilan Qi ◽  
Kamaljit Banger ◽  
...  
Keyword(s):  
Real Time ◽  
N Uptake ◽  
Growing Season ◽  
Weather Data ◽  
N Availability ◽  
Soil N ◽  
N Losses ◽  
Online Tool ◽  
Support Tool ◽  
Soil N Availability

Freshwater nitrogen (N) pollution is a significant sustainability concern in agriculture. In the U.S. Midwest, large precipitation events during winter and spring are a major driver of N losses. Uncertainty about the fate of applied N early in the growing season can prompt farmers to make additional N applications, increasing the risk of environmental N losses. New tools are needed to provide real-time estimates of soil inorganic N status for corn (Zea mays L.) production, especially considering projected increases in precipitation and N losses due to climate change. In this study, we describe the initial stages of developing an online tool for tracking soil N, which included, (i) implementing a network of field trials to monitor changes in soil N concentration during the winter and early growing season, (ii) calibrating and validating a process-based model for soil and crop N cycling, and (iii) developing a user-friendly and publicly available online decision support tool that could potentially assist N fertilizer management. The online tool can estimate real-time soil N availability by simulating corn growth, crop N uptake, soil organic matter mineralization, and N losses from assimilated soil data (from USDA gSSURGO soil database), hourly weather data (from National Weather Service Real-Time Mesoscale Analysis), and user-entered crop management information that is readily available for farmers. The assimilated data have a resolution of 2.5 km. Given limitations in prediction accuracy, however, we acknowledge that further work is needed to improve model performance, which is also critical for enabling adoption by potential users, such as agricultural producers, fertilizer industry, and researchers. We discuss the strengths and limitations of attempting to provide rapid and cost-effective estimates of soil N availability to support in-season N management decisions, specifically related to the need for supplemental N application. If barriers to adoption are overcome to facilitate broader use by farmers, such tools could balance the need for ensuring sufficient soil N supply while decreasing the risk of N losses, and helping increase N use efficiency, reduce pollution, and increase profits.

Seedbank Dynamics of Two Swallowwort (Vincetoxicum) Species

2017 ◽  
Vol 10 (2) ◽  
pp. 136-142 ◽  
Author(s):  
Antonio DiTommaso ◽  
Lindsey R. Milbrath ◽  
Scott H. Morris ◽  
Charles L. Mohler ◽  
Jeromy Biazzo
Keyword(s):  
United States ◽  
Management Strategy ◽  
Seedling Emergence ◽  
Soil Surface ◽  
Growing Season ◽  
First Year ◽  
Northeastern United States ◽  
The Third ◽  
Viable Seeds ◽  
Filled Seeds

Pale swallowwort and black swallowwort are European viny milkweeds that have become invasive in many habitats in the northeastern United States and southeastern Canada. A multiyear seedbank study was initiated in fall 2011 to assess annual emergence of seedlings and longevity of seeds of pale swallowwort and black swallowwort at four different burial depths (0, 1, 5, and 10 cm) over 4 yr. One hundred swallowwort seeds were sown in seed pans buried in individual pots, and emerged seedlings were counted and removed from May through September each year. A subset of seed pans was retrieved annually in October, and recovered seeds were counted and tested for viability. The majority of seedling emergence occurred during the first year (92% in 2012), and no new seedlings emerged in the third (2014) or fourth (2015) years. Pale swallowwort had relatively poor emergence at sowing depths of 0 cm (11%), 5 cm (6%), and 10 cm (0.05%—only one seedling), while 37% of pale swallowwort seeds emerged at 1 cm. The larger-seeded black swallowwort was more successful, with two-thirds of all sown seeds emerging at depths of 1 cm (71%) and 5 cm (66%), and 26% emerging at 10 cm. Only 16% of the surface-sown black swallowwort emerged. A large portion of the seeds that germinated at 10 cm, as well as at 5 cm for pale swallowwort, died before reaching the soil surface. Of filled seeds that were recovered in 2012 (black swallowwort at the 0-cm depth), 66% were viable. No viable seeds were recovered after the second growing season. Seeds recovered following the third year had become too deteriorated to accurately assess. Swallowwort seeds do not appear to survive more than 2 yr in the soil, at least in our experiment, suggesting that the elimination of seed production over 3 yr will exhaust the local seedbank. Seeds would need to be buried at least 10 cm for pale swallowwort but more than 10 cm for black swallowwort to prevent seedling emergence. Burial of swallowwort seeds as a management strategy may, however, only be practical in natural areas where high swallowwort densities occur.

DRY MATTER PRODUCTION AND NITROGEN ACCUMULATION IN NO-TILL WINTER WHEAT

1990 ◽  
Vol 70 (2) ◽  
pp. 461-472 ◽  
Author(s):  
B. A. DARROCH ◽  
D. B. FOWLER
Keyword(s):  
Winter Wheat ◽  
Nitrogen Fertilization ◽  
Dry Matter ◽  
N Uptake ◽  
Growing Season ◽  
Grain Protein ◽  
Soil N ◽  
N Yield ◽  
No Till ◽  
N Concentration

Norstar winter wheat (Triticum aestivum L.) was examined in 11 trials with the objective of determining the pattern of dry matter and nitrogen (N) accumulation in dryland stubbled-in winter wheat grown in Saskatchewan. In all 4 yr of this study, replicated no-till field trials were supplemented with 0, 34, 67 and 100 kg N ha−1 applied as ammonium nitrate (34-0-0) in early spring. A fifth treatment of 200 kg N ha−1 was evaluated in the final year of trials. Plant samples were collected at 2-wk intervals. Early season N uptake was more rapid than dry matter accumulation and 89% of the total N, compared to 70% of the total dry matter, was present at anthesis (Zadoks growth stages 60–68). Poor soil moisture availability limited N uptake after anthesis. Consequently, N uptake during the growing season was best described by a quadratic equation, Nitrogen yield = −29.1 + 3.02 Z − 0.018 Z2, where Z represents the Zadoks growth stage. Nitrogen concentrations of the stems and leaves decreased during the growing season while the N concentration of spikes varied among trials. Nitrogen fertilization often produced large increases in tissue N concentration at the beginning of the growing season. These differences decreased with time and by the end of the season tissue N concentrations were usually similar for all N rates. In general, when residual soil N levels were low to intermediate and rainfall was adequate, N fertilization increased dry matter yield, plant N yield, grain yield and grain protein yield. Nitrogen fertilization increased plant N concentration, plant N yield, grain protein concentration and grain protein yield when soil N reserves were intermediate to high and rainfall was adequate.Key words: Nitrogen uptake, wheat (winter), nitrogen response, tissue nitrogen, grain protein, environment

Effect of growing season rainfall and tillage on the uptake and recovery of 15N-labelled urea fertilizer by spring wheat in a semi-arid environment

2009 ◽  
Vol 89 (4) ◽  
pp. 403-411 ◽  
Author(s):  
S S Malhi ◽  
Y K Soon ◽  
S Brandt
Keyword(s):  
Spring Wheat ◽  
N Uptake ◽  
Growing Season ◽  
N Recovery ◽  
Soil N ◽  
Fertilizer N ◽  
Rainfall Distribution ◽  
Total N ◽  
Fertilizer N Recovery ◽  
Semi Arid

Growing season rainfall affects fertilizer N recovery, particularly in semi-arid environments. However, the influence of rainfall distribution during the growing season is not well-understood. We conducted a 7-yr study (from 1997 to 2006) to assess this effect, and that of no-till (NT) vs. conventional tillage (CT), on fertilizer N recovery by spring wheat (Triticum aestivum L.) fertilized with 15N-labelled urea at 40 kg N ha–1 and grown on stubble on a Dark Brown Chernozem soil in Saskatchewan, Canada. Two of the seven experimental years had growing season rainfall close to normal, one was above normal and four were below normal. Tillage treatment did not affect 15N recovery by wheat; however, 15N recovery in the top 15 cm of soil averaged 47% under NT vs. 39% under CT (P = 0.02). Total N and 15N uptakes were most affected by "year" due to variation in growing season rainfall distribution. Excluding an ultra-low value of 3.8% (or 1.5 kg N ha–1) in 2002, due to extreme drought, 15N recovery by wheat averaged 47.5% (range 30–57%), and percent N derived from fertilizer was 12–20%. Rainfall in May correlated significantly with 15N and total N uptake (r = 0.605 and 0.699, respectively). The recovery of 15N in wheat head correlated negatively with June rainfall (r = –0.624), probably because more moisture increased soil N mineralization, which diluted the 15N pool. During grain filling, soil N uptake was 12–30 kg ha–1, compared with negligible amounts (< 7%) of 15N; however, about 15 kg ha–1 of 15N were remobilized vs. 34–74 kg ha–1 of soil N. It is concluded that, in this semi-arid region, fertilizer N uptake is influenced more by rainfall in May than other months of the growth period.Key words: 15N-labelled urea, fertilizer N recovery, N uptake, rainfall, remobilized N, tillage

Clover and crop production under 13- to 15-year-old Pinus radiata

1979 ◽  
Vol 19 (98) ◽  
pp. 362 ◽  
Author(s):  
GW Anderson ◽  
FE Batini
Keyword(s):  
Pinus Radiata ◽  
Crop Production ◽  
Subterranean Clover ◽  
Growing Season ◽  
Tree Density ◽  
First Year ◽  
Adjacent Area ◽  
The Third ◽  
One Year ◽  
Seed Yields

A thirteen-year-old Pinus radiata plantation was thinned to 143 or 261 stems ha-1 and pruned to 6 m at Mundaring, Western Australia. The production of the Daliak, Seaton Park and Woogenellup cultivars of subterranean clover sown under the trees and on an adjacent area under pasture only was measured for two years. The yields of oats and lupins sown for two successive years following one year of clover pasture were also measured. No seedling establishment problems were encountered and healthy, productive pastures resulted. In the first year, Daliak was inferior to the other cultivars for both herbage and seed production. Seed yields were highest under the low tree density. By the third growing season herbage yields had fallen under the trees to 84% of the control pastures (4800 kg ha-1) at 143 stems ha-1 and 68% at 261 stems ha-1. The yields of oats were usually higher on the control plots but those of lupins seldom so.

Impact of lupins, grazed or ungrazed subterranean clover,stubble retention, and lime on soil nitrogen supplyand wheat nitrogen uptake, grain yields, and grain protein

1998 ◽  
Vol 49 (3) ◽  
pp. 487 ◽  
Author(s):  
W. J. McGhie ◽  
D. P. Heenan ◽  
D. Collins
Keyword(s):  
Grain Yield ◽  
Soil Nitrogen ◽  
N Uptake ◽  
Subterranean Clover ◽  
Growing Season ◽  
Grain Protein ◽  
Soil N ◽  
Grain Yields ◽  
Total Soil ◽  
Total Soil N

Soil nitrogen (N), N uptake, and wheat production in relation to rotation with wheat, lupin,or subterranean clover, mulched or grazed, were examined on a red earth at Wagga Wagga, New South Wales. Data over 4 years (1992{95) are presented from a long-term trial commenced in 1979. The effects of the various rotations on wheat productivity changed with seasonal rainfall duringthe wheat and the previous legume growing year. Generally, low rainfall (1991 and 1994) during thelegume growing season resulted in lower N uptake, grain protein, and grain yield by wheat grown ina following season. The addition of N fertiliser (100 kg N/ha) to continuous wheat increased soil N supply, N uptake, grain yield, and grain protein. Yields from continuously cropped wheat fertilisedwith N were usually lower than those after a lupin growing season, although total soil N levels weresimilar. Subterranean clover produced higher total soil N and grain protein than lupin but yields werenormally less. Lodging and take-all diseases were higher after a growing season with subterraneanclover than after lupins and most likely reduced grain yields. Grazing, as opposed to mowing andmulching subterranean clover, increased soil total N, grain protein, and usually soil mineral N, butnot grain yield. The addition of lime at 1·5 t/ha raised the soil pH(CaCl2) (0-10 cm) of the mostacidified treatment, continuously cropped wheat fertilised with N, from 4·04 to a mean of 4·7, andincreased yields and N uptake in 1993 and 1995.

scholarly journals Water Requirements and Growth of Irrigated Hybrid Poplar in a Semi-Arid Environment in Eastern Oregon

2002 ◽  
Vol 17 (1) ◽  
pp. 46-53 ◽  
Author(s):  
Clinton C. Shock ◽  
Erik B.G. Feibert ◽  
Majid Seddigh ◽  
Lamont D. Saunders
Keyword(s):  
Water Potential ◽  
Soil Water ◽  
Soil Water Potential ◽  
Hybrid Poplar ◽  
Arid Environment ◽  
First Year ◽  
State University ◽  
Potential Growth ◽  
The Third ◽  
Application Rates

Abstract Potential growth of poplar (Populus deltoidesP. nigra.) is highly dependent on the amount of applied irrigation and soil moisture. Hybrid poplar (cultivar OP-367) was planted at 222 trees/ac in April 1997 at the Oregon State University Malheur Experiment Station near Ontario, OR. Six irrigation treatments included a combination of soil water potentials as thresholds for initiating irrigation and varying water application rates. Water was applied via micro-sprinklers installed along the tree rows. Results indicated that for optimum poplar growth, soil water potential at an 8 in. depth should average above -20 kPa (kPa = cbar) during the growing season. This was achieved by irrigating when the soil water potential reached -25 kPa and applying 21 ac-in./ac of irrigation water during the first year, 35 ac-in./ac during the second year, and 44 ac-in./ac during the third year. By the end of the third year, trees receiving optimum irrigation averaged 26 ft tall and produced 256 ft3 of wood/ac. West. J. Appl. For. 17(1):46–53.

Type and Timing of Thinning Hybrid Poplar Coppice Affects Growth

1991 ◽  
Vol 8 (4) ◽  
pp. 166-168 ◽  
Author(s):  
Norman Druck ◽  
Silvia Strobl
Keyword(s):  
Wood Fiber ◽  
Hybrid Poplar ◽  
Growing Season ◽  
Operational Efficiency ◽  
The Third ◽  
Growing Seasons ◽  
Eastern Ontario ◽  
Sprout Growth

Abstract To optimize the growth of a hybrid poplar coppice plantation, a thinning trial was established in eastern Ontario. Four treatments were investigated: (1) thinning stools to one dominant sprout with residuals clipped at a height of 1 m (to increase operational efficiency of thinning), (2) thinning to one dominant sprout with residuals completely removed, (3) thinning to three dominant sprouts with residuals completely removed, and (4) no thinning. All treatments were performed at the beginning of either the third or fifth growing seasons (timing treatment one and two, respectively). When the 7-yr-old data were analyzed (i.e., 5 growing seasons after timing treatment one and 3 growing seasons after timing treatment two), thinning did not increase dominant sprout growth and significantly larger quantities of wood fiber were produced with lower thinning intensities or no thinning because of the greater number of sprouts per stool. Results of this trial suggest there is no advantage to thinning hybrid poplar coppice after the beginning of the third growing season. North. J. Appl. For. 8(4):166-168.

Availability of nitrogen from municipal biosolids for dryland forage grass

2000 ◽  
Vol 80 (3) ◽  
pp. 575-582 ◽  
Author(s):  
B. J. Zebarth ◽  
R. McDougall ◽  
G. Neilsen ◽  
D. Neilsen
Keyword(s):  
N Uptake ◽  
Forage Yield ◽  
Nitrate Content ◽  
First Year ◽  
Forage Grass ◽  
N Mineralisation ◽  
Soil N ◽  
Total N ◽  
Available N ◽  
Municipal Biosolids

A 3-yr study, initiated in 1996, evaluated the availability of N from applied biosolids for dryland forage grass production under the cool, continental climatic conditions in central British Columbia. Treatments included 600 (LB), 1200 (MB) and 1800 (HB) kg total N ha−1 applied as municipal biosolids, a single application of 150 kg N ha−1 as urea in the first year of the experiment (SF), a multiple application of 150, 60 and 30 kg N ha−1 as urea in the first, second, and third years of the experiment (MF), and a control that received no biosolids or urea. All treatments were roto-tilled to 15-cm depth and seeded to a mixture of four grasses. The LB treatment was predicted to supply a similar quantity of plant-available N as the MF treatment, assuming 25, 10, and 5% of biosolids N is available in the first, second, and third year, respectively. Soil N fertility was poor as indicated by the very low forage yield and N uptake in the control, and minimal apparent net soil N mineralisation. Recovery of urea N in the crop over 3 yr averaged only 27%, likely reflecting net immobilisation in this recently broken site and accumulation of N in non-harvested portions of the crop. Cumulative recovery of N from biosolids in the harvested forage averaged only 11%. However, the fertiliser N equivalency of the biosolids N (ratio of recovery of biosolids N to urea N) was estimated at 41%, close to the predicted value of 40%. Forage yield and N uptake were similar for the LB and MF treatments, suggesting that actual biosolids N availability was similar to that predicted. Limited forage yield increase for the HB compared with the MB treatment early in the experiment, and high forage nitrate content for the HB treatment in the first year, suggest that the HB treatment initially supplied an excessive quantity of N. Both urea and biosolids applications increased cumulative uptake of other macro- and micro-nutrients, with forage Cu concentrations reaching values in the establishment year that may be of concern for some animal species. Monitoring of forage NO3 and Cu concentrations is advisable where biosolids are applied. Key words: Phleum pratense L., Dactylis glomerata, Bromus inermis, Bromus biebersteinii, soil N mineralisation, NO3 toxicity

Seasonal variation in the suitability of different methods for estimating biological nitrogen fixation by grain legumes under rainfed conditions

1996 ◽  
Vol 47 (7) ◽  
pp. 1061 ◽  
Author(s):  
AM McNeill ◽  
CJ Pilbeam ◽  
HC Harris ◽  
RS Swift
Keyword(s):  
Nitrogen Fixation ◽  
Isotope Dilution ◽  
Biological Nitrogen Fixation ◽  
N Uptake ◽  
Isotope Dilution Method ◽  
Dilution Method ◽  
First Year ◽  
Soil N ◽  
A Value ◽  
Biological Nitrogen

Biological nitrogen fixation (BNF) by legume crops was estimated in a Mediterranean environment at ICARDA in northern Syria for 3 consecutive seasons beginning in 1991-92. Using the classical isotope dilution technique (NID), estimates ranged from 32 to 82 kg N/ha for chickpea and from 18 to 82 kg N/ha for lentil. In comparison the simple N-difference method gave lower, sometimes negative, estimates for BNF by both crops in the latter 2 seasons but a higher estimate for chickpea in the first year. Discrepancies in the estimates from N-difference were correlated with differences in the amount of soil N taken up by the legume and the non-fixing wheat reference crop. Since soil N uptake by lentil in the first year was similar to wheat, the estimates of BNF from the 2 methods for that season were similar. The indirect effects of an interaction of added N fertiliser on N derived from the soil and thus on N uptake and estimated BNF are discussed in relation to the use of the isotope dilution method with A-value modification (NAV). Despite some significant differences in A-value for soils receiving different amounts of fertiliser it is demonstrated that the A-value method used in this study, with fertiliser rates of 10 kg N/ha to the legume and 30 kg N/ha to the non-legume, resulted in BNF estimates for lentil similar to those obtained using classical isotope dilution. However, this was not the case for chickpea where a direct inhibitory effect of fertiliser N at 30 kg N/ha resulted in lower estimates of BNF from NID than NAV. Since the reference crops derived as much as 90% of their N from the soil, it is recommended that future BNF studies using isotope dilution techniques for lentil and chickpea crops at ICARDA use a fertiliser rate lower than that used in this study. An isotope dilution method utilising a slow-release source of 15N or the natural abundance technique for estimating BNF are suggested as potentially useful alternatives. The need for a basic understanding of the soil N dynamics pertinent to each site as a prerequisite for choosing an appropriate method for estimating BNF is highlighted.

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