scholarly journals Changes in Nitrogen Mineralization, Tissue Nutrient Concentrations and Biomass Compartmentation after Cessation of Fertilizer Application to Mown Grassland

1994 ◽  
Vol 82 (3) ◽  
pp. 611 ◽  
Author(s):  
Han Olff ◽  
Frank Berendse ◽  
Willem De Visser
HortScience ◽  
2017 ◽  
Vol 52 (12) ◽  
pp. 1728-1733 ◽  
Author(s):  
Martin M. Maboko ◽  
Christian Phillipus Du Plooy ◽  
Silence Chiloane

Nutrient application is one of the major inputs required for hydroponic production of cucumbers. Reduced nutrient solution concentration with supplementary foliar fertilizer application may maintain yield and quality of mini-cucumber, while decreasing the production costs. An experiment was conducted to determine the effect of foliar fertilizer in combination with reduced nutrient concentrations on the yield and quality of hydroponically grown mini-cucumber in a plastic tunnel. Mini-cucumber plants were grown in sawdust, fertigated with nutrient solutions containing 100% (control), 75%, 50%, or 25% of the recommended nutrient concentration (NC) and two foliar fertilizer applications (no foliar and foliar application). The highest fresh and dry weight of mini-cucumber plants were obtained with 75% and 100% NC and decreased with 50% to 25% NC application. The number of marketable fruit and marketable yield on mini-cucumbers increased with 75% to 100% NC, followed by 50% NC, as compared with 25% NC. Deformed fruit were significantly lower at 25% NC than at 50%, 75%, and 100% NC. Foliar fertilizer application did not have an effect on mini-cucumber yield, but reduced the yellowing of fruit. Fruit mineral content (P, Fe, and Mn) was significantly improved by 100% NC. Improvement in yield at 75% and 100% NC was as a result of improved plant height, leaf chlorophyll content, plant fresh and dry weight, and the increase in nutrient uptake of N, P, K, and Mn, which was evident in the analysis of cucumber leaves. The reduced NC of 75% can maintain yield and quality of mini-cucumbers, whereas the application of foliar fertilizer had a limited effect.


2000 ◽  
Vol 30 (9) ◽  
pp. 1341-1352 ◽  
Author(s):  
C E Prescott ◽  
L Vesterdal ◽  
J Pratt ◽  
K H Venner ◽  
L M de Montigny ◽  
...  

We examined the extent to which nutrient concentrations and C and N mineralization rates in forests floors under different tree species are predictable from the chemistry of foliar litter and its rate of decomposition. We studied replicated single species plantations of western redcedar (Thuja plicata Donn ex D. Don), western hemlock (Tsuga heterophylla (Raf.) Sarg.), Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco), and Sitka spruce (Picea sitchensis (Bong.) Carr.) at four locations. Nutrient concentrations in forest floors correlated poorly with litter nutrient concentrations; the only significant relationships were for Ca and K. Nitrogen mineralization correlated weakly with forest floor C/N ratio, and differed more among sites than among species. None of the litter chemistry parameters were related to net N mineralization rates. Decomposition was fastest in hemlock litter, intermediate in Douglas-fir litter and lowest in cedar litter. Litter also decomposed more rapidly on hemlock forest floors than on cedar forest floors. Rates of N mineralization in the forest floors were not related to rates of decomposition of foliar litter. Differences among sites in N mineralization rates were related to the understory vegetation composition, particularly the amount of the ericaceous shrub salal, which in turn was related to slope position. These site factors appeared to override the effect of tree species on rates of N mineralization.


2002 ◽  
Vol 138 (3) ◽  
pp. 301-310 ◽  
Author(s):  
A. COLLINS ◽  
D. W. ALLINSON

Under perennial grasslands, nitrogen contained in organic matter becomes available at varying rates via mineralization throughout the growing season. The amount of N present at any given time indicates only the quantity immediately present, and does not include N which has already been removed either by leaching or uptake into the plant system, nor the N which will become available as organic matter breaks down over time. Long-term aerobic laboratory incubation methods have been used successfully to estimate potential N mineralization under various cropping conditions. They had not been used successfully, however, to estimate potential N availability under perennial grassland.In this research, soil samples from two long-term perennial grassland sites were taken before and after N fertilizer application at rates of 0, 175, 350 and 525 kg/ha. The soils were incubated in the laboratory at 35 °C and were eluted at 2, 4, 8, 12, 16, 22 and 30-week intervals, the length of time prescribed for determining N mineralization potential. Because a plateau had not been reached, incubation was allowed to continue for 198 weeks and 148 weeks for the pre- and post-N samples, respectively. Total N was high, as was soil organic matter in both sets of soil samples. Nitrogen mineralization potential was underestimated after 30 weeks of incubation, and overestimated after 148 weeks. The closest agreement between N measured and the estimated N mineralization potential, came after 198 weeks of incubation. This study confirmed the high N-supplying capacity of soil under long-term perennial grasslands. It also indicated that the recommended 30-week period needed to estimate N mineralization potential under other cropping systems was insufficient for a perennial grassland soil. Cumulative differences in N mineralization were found with varying rates of N fertilizer application, but these differences were rarely seen on an individual weekly basis, nor were they significant at the termination of the experiment. The response to N application differed by site.


Soil Research ◽  
1983 ◽  
Vol 21 (2) ◽  
pp. 139 ◽  
Author(s):  
NB Greenhill ◽  
KI Peverill ◽  
LA Douglas

Concentrations of nitrogen and phosphorus forms, calcium, sulfur and potassium in runoff from previously fertilized plots were explained on the basis of differences in slope, previous fertilizer history, and land management at three runoff sites. Data are also given for concentrations of nitrogen and phosphorus forms, calcium, sulfur and potassium in runoff that occurred after superphosphate was applied. High concentrations of phosphorus forms, calcium and sulfur occurred in runoff from a storm 24 h after fertilizer application. At other times, concentrations of all measured parameters were low, and similar to those reported elsewhere.


HortScience ◽  
2014 ◽  
Vol 49 (2) ◽  
pp. 152-159 ◽  
Author(s):  
Christopher J. Currey ◽  
Roberto G. Lopez

Our objectives were to quantify the effects of controlled-release fertilizer (CRF) on the growth, morphology, and tissue nutrient concentration of annual bedding plants during propagation. Unrooted cuttings of Angelonia angustifolia ‘AngelFace White’ and ‘Sundancer Pink’, Impatiens hawkeri ‘Celebrette Apricot’ and ‘Celebrette Rose Hot’, Nemesia fruticans ‘Bluebird’ and ‘Raspberry Sachet’, Pelargonium ×hortorum ‘Savannah Red’, and Petunia ×hybrida ‘Cascadia Marshmallow Pink’ and ‘Suncatcher Yellow’ were received from a commercial propagator. Cuttings were immediately stuck individually in cells containing soilless substrate supplemented with 0, 3, 6, 12, or 24 g·L−1 CRF (Osmocote Plus 15–3.9–10 3–4 month) and placed under clear mist water or cuttings were stuck in substrate containing no CRF and fertilized with water-soluble fertilizer beginning immediately after placing cuttings into propagation. Shoot dry mass of cuttings grown in substrates containing up to 12 or 24 g·L−1 CRF increased by up to 150% for some taxa compared with unfertilized cuttings. Incorporating CRFs into propagation substrates increased the concentration of nitrogen (N), phosphorus (P), and potassium (K) in tissues by up to 103%, 42%, and 137%, respectively, compared with unfertilized cuttings. Additionally, tissue nutrient concentrations for cuttings fertilized with 6 g·L−1 CRF or greater were similar to cuttings receiving water-soluble fertilizer (WSF). When the impact of CRF on growth and nutrient concentrations are taken together, our results indicate that CRF is a fertilization application technology that holds promise for use during propagation of herbaceous stem-tip cuttings.


HortScience ◽  
2011 ◽  
Vol 46 (5) ◽  
pp. 799-807 ◽  
Author(s):  
Gladis M. Zinati ◽  
John Dighton ◽  
Arend-Jan Both

We tested the effects of using an inoculum containing natural ericoid roots and soil (NERS) with two fertilizer and irrigation rates on plant growth, shoot (stems and leaves) nutrient concentration, leachate quality, and mycorrhizal colonization of container-grown Coast Leucothoe [Leucothoe axillaris (Lam.) D. Don] and Japanese Pieris [Pieris japonica (Thunb.) D. Don ex G. Don]. Uniform rooted liners were grown in 10.8-L containers in a pine bark, peatmoss, and sand (8:1:1 by volume) substrate medium in a randomized complete block design with four replications. A controlled-release fertilizer, Polyon® Plus 14-16-8 (14N–7P–6.6K), was incorporated in the substrate medium at the 100% manufacturer's recommended fertilizer rate [representing high fertilizer rate (HF)] (56 g per container) to supply 7.84 g nitrogen (N) and at 50% the manufacturer's recommended rate [representing low fertilizer rate (LF)]. Plants were irrigated using a cyclic drip irrigation system at high (HI) and low (LI) irrigation rates calibrated to supply 25.2 L of water and 16.8 L per week, respectively. On average, NERS inoculation increased shoot growth of Leucothoe and Pieris by 56% and 60%, respectively. Shoots of Leucothoe inoculated with NERS had higher N, phosphorus (P), magnesium (Mg), and manganese (Mn) concentrations than non-inoculated plants. At LF, nitrous-N (NOx-N) and orthophosphorus (PO4-P) concentrations in the leachate were reduced by 53% from Leucothoe and 62% from Pieris compared with HF-treated plants. A reduction of 37% and 36% in PO4-P concentration in leachates from Leucothoe and Pieris, respectively, were achieved at the reduced irrigation (LI) rate. The NERS inoculation reduced PO4-P concentrations in leachate from Leucothoe by 26% and NOx-N concentration by 33% in leachates from Pieris compared with non-inoculated plants. Compared with plants grown in the HI–HF treatment, the combination of LI–LF treatment reduced NOx-N concentrations in leachates from Leucothoe by 60% (P = 0.016) and reduced PO4-P leachate concentrations from Pieris by 72% (P = 0.0096). Decreasing the fertilizer rate to 50% of the recommended rate and the irrigation rate to 67% of the recommended rate in conjunction with the incorporation of NERS reduced leachate nutrient concentrations of two main water pollutants (NOx-N and PO4-P). Adopting the practice of adding NERS containing fungi and bacteria can be an effective system to increase shoot dry weight, allow reduction in fertilizer application, conserve water for irrigation, and minimize subsequent nutrient runoff in nursery operations.


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