NUTRIENT DISTRIBUTION IN FOREST SOIL LEACHATES AFTER THINNING AND FERTILIZING DOUGLAS-FIR FOREST

1982 ◽  
Vol 62 (1) ◽  
pp. 197-208 ◽  
Author(s):  
P. C. PANG ◽  
K. McCULLOUGH
Keyword(s):  
Nitrogen Fertilization ◽  
Forest Floor ◽  
Unit Area ◽  
Nitrate Concentration ◽  
Nutrient Distribution ◽  
Plate Method ◽  
Area Basis ◽  
Forest Floor Leachates ◽  
Urea Fertilization ◽  
Nitrate Fertilization

The nutrients NH4+, NO3−, Ca2+, Mg2+ and K+ in leachates from immediately below the forest floor and from the mineral horizons at 10- and 30-cm depths were monitored with tension lysimeter plates held at 10 ± 1.0 kPa. Experimental plot treatments were thinning, fertilizing with nitrogenous fertilizers (448 kg N∙ha−1), and both. Concentrations (mg∙L−1) of these nutrients in the forest floor leachates increased immediately following nitrogen fertilization, but returned to near those of untreated levels about 5–10 mo later. Concentrations fluctuated at 10- and 30-cm depths in the mineral horizons. With urea fertilization, the increases in concentrations of nutrients were primarily associated with the forest floor. Nitrate concentration of 200 mg N∙L−1 in the forest floor leachate 5 mo after urea fertilization compared to 0.1–0.5 mg N∙L−1 of the untreated, indicated that nitrification had taken place. With ammonium nitrate fertilization, substantially higher concentrations of NO3−, Ca2+, Mg2+, and K+ were detected at 10- and 30-cm depths compared with urea fertilization. Thinning, when combined with urea fertilization, enhanced the movement of nutrients to greater depth in the soil profile. On a unit area basis (kg∙ha−1) the leaching of nutrients from soil horizons could be overestimated by the tension lysimeter plate method, as these plates do not only draw soil water from directly above.

scholarly journals Volume and Nutrient Transports Disturbed by the Typhoon Chebi (2013) in the Upwelling Zone East of Hainan Island, China

2021 ◽  
Vol 9 (3) ◽  
pp. 324
Author(s):  
Manli Zheng ◽  
Lingling Xie ◽  
Quanan Zheng ◽  
Mingming Li ◽  
Fajin Chen ◽  
...  
Keyword(s):  
South China Sea ◽  
Coastal Upwelling ◽  
Unit Area ◽  
Hainan Island ◽  
Volume Transport ◽  
Coastal Ocean ◽  
Offshore Water ◽  
Nutrient Distribution ◽  
Before And After ◽  
Ekman Flow

Using cruise observations before and after the typhoon Chebi in August 2013 and those without the typhoon in July 2012, this study investigates variations in current structure, nutrient distribution, and transports disturbed by a typhoon in a typical coastal upwelling zone east of Hainan Island in the northwestern South China Sea. The results show that along-shore northeastward flow dominates the coastal ocean with a volume transport of 0.64 × 106 m3/s in the case without the typhoon. The flow reversed southwestward, with its volume transport halved before the typhoon passage. After the typhoon passage, the flow returned back northeastward except the upper layer in waters deeper than 50 m and the total volume transport decreased to 0.10 × 106 m3/s. For the cross-shelf component, the flow kept shoreward, while transports crossing the 50 m isobath decreased from 0.25, 0.12 to 0.06 × 106 m3/s in the case without the typhoon as well as before and after typhoon passage, respectively. For the along-shore/cross-shelf nutrient transports, SiO32− has the largest value of 866.13/632.74 μmol/s per unit area, NO3− half of that, and PO43− and NO2− one order smaller in the offshore water without the typhoon. The values dramatically decreased to about one-third for SiO32−, NO3−, and PO43− after the typhoon, but changed little for NO2−. The disturbed wind field and associated Ekman flow and upwelling process may explain the variations in the current and nutrient transports after the typhoon.

Nitrogen fertilization stimulates germination of dormant pin cherry seed

1979 ◽  
Vol 9 (4) ◽  
pp. 514-516 ◽  
Author(s):  
L. R. Auchmoody
Keyword(s):  
Ammonium Sulfate ◽  
Nitrogen Fertilization ◽  
Forest Floor ◽  
Calcium Nitrate ◽  
Nitrogen Fertilizers ◽  
Triple Superphosphate ◽  
Breaking Dormancy ◽  
Muriate Of Potash

Nitrogen fertilizers triggered germination of dormant Prunuspensylvanica L. seed naturally buried in the forest floor of 60-year-old Allegheny hardwood stands. Neither triple superphosphate nor muriate of potash applied with urea increased germination over that which occurred with urea alone. Rates as low as 56 kg/ha N from urea and calcium nitrate and 112 kg/ha N from ammonium sulfate stimulated germination. Nitrate was apparently responsible for breaking dormancy.

scholarly journals Nitrogen fertilization of vegetables cultivated under no-tillage after cover crops

2017 ◽  
Vol 35 (1) ◽  
pp. 103-110 ◽  
Author(s):  
Roberto BF Branco ◽  
Sally F Blat ◽  
Tais GS Gimenes ◽  
Rodrigo HD Nowaki ◽  
Humberto S Araújo ◽  
...  
Keyword(s):  
Plant Growth ◽  
Cover Crops ◽  
Nitrogen Fertilization ◽  
Nitrate Concentration ◽  
Dry Mass ◽  
Growth And Yield ◽  
No Tillage ◽  
Biological Fixation ◽  
Sunn Hemp ◽  
Nitrogen Rates

ABSTRACT The production of horticultural crops in no-tillage and in rotation with cover crops reduces the dependency in nitrogen fertilizer, due to increased soil organic matter and by biological fixation performed by legumes. Thus, the aim of this work was to study rates of nitrogen fertilization and cover crops in the agronomic performance of tomato and broccoli grown under no-tillage. The experiment was conducted in a split plot design with four replications. Treatments consisted of cover crops, sunn hemp and millet, and four rates of nitrogen fertilization (0, 50, 100 and 200 kg/ha of nitrogen), for both the tomato and broccoli crops. All soil management was performed in no-tillage. For tomato crops we evaluated the plant growth, the nitrate concentration of sprouts and fruits and yield of commercial and non commercial fruits. For broccoli we evaluated plant growth and yield. There was an interaction effect between cover crop and nitrogen rates to tomato growth measured at 100 days after transplanting, for plant height, number of fruit bunches, dry mass of leaves and diameter of the stalk. The tomato commercial fruit number and yield showed maximum values with 137 and 134 kg/ha of N respectively, on the sunn hemp straw. The nitrate concentration of the tomato sprouts was linearly increasing with the increase of nitrogen rates, when grown on the millet straw. For broccoli production, the maximum fresh mass of commercial inflorescence was with 96 kg/ha of N, when grown on the millet straw.

scholarly journals Dynamic of nitrogen and dissolved organic carbon in an alpine forested catchment: atmospheric deposition and soil solution trends

2019 ◽  
Vol 34 ◽  
pp. 41-66 ◽  
Author(s):  
Raffaella Balestrini ◽  
Carlo Andrea Delconte ◽  
Andrea Buffagni ◽  
Alessio Fumagalli ◽  
Michele Freppaz ◽  
...  
Keyword(s):  
Soil Solution ◽  
Forest Ecosystem ◽  
Forest Floor ◽  
Mineral Soil ◽  
Chemical Species ◽  
Organic N ◽  
Seasonal Temperature ◽  
Inorganic N ◽  
Forest Floor Leachates ◽  
Throughfall Deposition

A number of studies have reported decreasing trends of acidifying and N deposition inputs to forest areas throughout Europe and the USA in recent decades. There is a need to assess the responses of the ecosystem to declining atmospheric pollution by monitoring the variations of chemical species in the various compartments of the forest ecosystem on a long temporal scale. In this study, we report on patterns and trends in throughfall deposition concentrations of inorganic N, dissolved organic N (DON) and C (DOC) over a 20-year (1995–2015) period in the LTER site -Val Masino (1190 m a.s.l.), a spruce forest, in the Central Italian Alps. The same chemical species were studied in the litter floor leachates and mineral soil solution, at three different depths (15, 40 and 70 cm), over a 10-year period (2005–2015). Inorganic N concentration was drastically reduced as throughfall and litter floor leachates percolated through the topsoil, where the measured mean values (2 µeq L-1) were much lower than the critical limits established for coniferous stands (14 µeq L-1). The seasonal temperature dependence of throughfall DOC and DON concentration suggests that the microbial community living on the needles was the main source of dissolved organic matter. Most of DOC and DON infiltrating from the litter floor were retained in the mineral soil. The rainfall amount was the only climatic factor exerting a control on DOC and N compounds in throughfall and forest floor leachates over a decadal period. Concentration of SO4 and NO3 declined by 50% and 26% respectively in throughfall deposition. Trends of NO3 and SO4 in forest floor leachates and mineral soil solution mirrored declining depositions. No trends in both DON and DOC concentration and in DOC/DON ratio in soil solutions were observed. These outcomes suggest that the declining NO3 and SO4 atmospheric inputs did not influence the dynamic of DON and DOC in the Val Masino forest. The results of this study are particularly relevant, as they are based on a comprehensive survey of all the main compartments of the forest ecosystem. Moreover, this kind of long-term research has rarely been carried out in the Alpine region.

Effects of Fertilizer and Clipping on protein in Leaves of Desert Grasses

1979 ◽  
Vol 15 (1) ◽  
pp. 103-106 ◽  
Author(s):  
S. Kathju ◽  
K. A. Shankarnarayan ◽  
A. N. Lahiri ◽  
S. P. Vyas
Keyword(s):  
Soil Fertility ◽  
Nitrogen Fertilization ◽  
Unit Area ◽  
Arid Zone ◽  
Maximum Yield ◽  
Short Intervals ◽  
Fertility Status ◽  
Nitrogenous Fertilizer ◽  
Extractable Protein ◽  
Soil Fertility Status

SUMMARYThe effects of nitrogen fertilization and cutting intervals on extractable protein have been studied in three arid zone grasses, viz. Cenchrus setigerus, C. ciliaris and Lasiurus sindicus. Depending on the number of cuts and soil fertility status, maximum protein could be harvested from C. ciliaris followed by C. setigerus and L. sindicus. It is concluded that the maximum yield of leaf protein per unit area of land can be achieved with short intervals of cutting coupled with the application of nitrogenous fertilizer.

RELATIONSHIP BETWEEN MICROBIAL NUMBERS AND DROPLET SIZE IN AERIAL SPRAY APPLICATIONS

1977 ◽  
Vol 109 (10) ◽  
pp. 1319-1323 ◽  
Author(s):  
O. N. Morris
Keyword(s):  
Active Ingredient ◽  
Inclusion Bodies ◽  
Drop Size ◽  
Unit Area ◽  
Agar Plate ◽  
Ground Level ◽  
Aerial Application ◽  
Plate Method ◽  
The Relationship ◽  
Entomopathogenic Viruses

AbstractExperiments were designed to determine the actual number of spores and crystals of Bacillus thuringiensis (B.t.) and of nuclear polyhedral virus and entomopoxvirus deposited at ground level per unit area and to determine any change in spore:crystal ration following aerial application in forested plots.The results indicate that: (1) The estimation of B.t. aerial spray deposits by the commonly used agar plate method grossly underestimates the deposit rates of active ingredient. The tracer dye method more accurately estimates deposit rates for both B.t. and entomopathogenic viruses. As a dye 0.1% Erio Acid Red XB is recommended. (2) The relationship between drop size and the number of spores and crystals or virus inclusion bodies/drop is curvilinear. This relationship probably holds true regardless of spray volume rate. All visible spray deposits at ground level contained some active ingredient. (3) With B.t. sprays the sporexrystal ratio emitted from the aircraft is not changed upon target impact.

Ammonia Volatilization from some Forest Floor Materials Following Urea Fertilization

1975 ◽  
Vol 5 (2) ◽  
pp. 210-216 ◽  
Author(s):  
M. K. Mahendrappa
Keyword(s):  
Concentration Gradient ◽  
Forest Floor ◽  
Ammonia Volatilization ◽  
Experimental Period ◽  
Hardwood Forest ◽  
Forest Stands ◽  
Urea Nitrogen ◽  
Organic Layers ◽  
Ph Values ◽  
Urea Fertilization

Ammonia volatilization from urea-treated organic layers of four softwood and three hardwood forest stands was investigated under laboratory conditions. All samples were treated with urea at rates equivalent to 168, 336, and 500 kg N per hectare. In addition, samples from a jack pine (Pinusbanksiana) stand were treated with urea at rates equivalent to 1100 and 1680 kg N per hectare (1 ha = 104 m2). At the end of a 7-day volatilization period the pH values of L and F + H layers were determined.In both softwood and hardwood samples, the proportions of added N volatilized as ammonia were larger when higher dosages of urea were applied. It is suggested that the rate of ammonia volatilization is determined by the concentration gradient of urea in solution around the sites where the enzyme urease hydrolyses urea. Less ammonia was evolved from hardwood than from softwood organic layers. Ammonia volatilization from softwood and hardwood organic layers treated with 336 kg N per hectare in urea was 0.41 to 3.75 and 0.16 to 1.76% of the added N, respectively. At the end of the experimental period the pH values of the L layers were generally higher than those of the F + H layers. The organic layers from the hardwood stands showed a smaller shift in pH than those from the softwood stands treated with the same levels of urea nitrogen.

NITROGEN TRANSLOCATION IN AN ORTHIC FERRO-HUMIC PODZOL AFTER UREA FERTILIZATION

1989 ◽  
Vol 69 (2) ◽  
pp. 437-440 ◽  
Author(s):  
D. E. SWIFT ◽  
H. H. KRAUSE
Keyword(s):  
Nutrient Cycling ◽  
Forest Floor ◽  
C:N Ratio ◽  
High Rate ◽  
Fertilizer N ◽  
Forest Fertilization ◽  
Total N ◽  
Indigenous Forest ◽  
Urea Fertilization ◽  
N Status

Sampling of soil 9 yr after a high-rate urea application showed a significant increase in total N content and a decrease of the C:N ratio in the Bhf horizon. This change corresponded to a gain of 368 kg of N ha−1 in the 3-cm thick, sampled portion of this horizon. The changes in N status were accompanied by a general darkening of the soil. It is assumed that both fertilizer N and indigenous forest floor N were translocated to the B Horizon after the treatment. Key words: Forest fertilization, nitrogen, nutrient cycling, urea

Contact Stiffness of New and Worn Surfaces

2005 ◽  
Author(s):  
A. Soom ◽  
C. I. Serpe
Keyword(s):  
Unit Area ◽  
Contact Stiffness ◽  
Measured Data ◽  
Wear Particles ◽  
Subsurface Cracks ◽  
Nominal Pressure ◽  
Resonance Frequencies ◽  
Area Basis ◽  
Steel Surfaces ◽  
Rough Surface Contact

The presence of surface texture/roughness on engineering surfaces results in contacts between surfaces being considerably more compliant than if the interfaces were smooth and flat. The inclusion of a local contact stiffness can be critical to the accurate analytical or computational modeling of mechanical contacts. We present measurements of contact stiffness for five pairs of freshly prepared and worn of steel surfaces. The wom surfaces variously contain surface glazes, oxide layers, subsurface cracks, inclusions and wear particles. Contact resonance frequencies between sample interfaces are measured at various applied pressures. With known modal masses, the contact stiffness is easily calculated and presented on a per unit area basis. For a given contact pair, the contact stiffness is nonlinear, increasing with nominal pressure and decreasing with increasing surface roughness. We compare these results with the Greenwood-Williamson (G-W) Theory of rough surface contact. The expected pressure and summit height dependencies are observed in the measured data. When there are wear particles within the contact, the stiffness is reduced when the underlying surfaces are very smooth. If the underlying surfaces are rough, the presence of wear particles have little effect on the contact stiffness.

Sign in / Sign up

Export Citation Format

Share Document