A nutrient balance model (NuBalM) to predict biomass and nitrogen pools in Pinus radiata forests

2011 ◽  
Vol 262 (2) ◽  
pp. 270-277 ◽  
Author(s):  
Simeon J. Smaill ◽  
Peter W. Clinton ◽  
Barbara K. Höck
Keyword(s):  
Pinus Radiata ◽  
Nutrient Balance ◽  
Balance Model ◽  
Nitrogen Pools

scholarly journals Fertigation based on a nutrient balance model for cassava production in two different textured soils

2020 ◽  
Vol 23 (4) ◽  
pp. 407-416 ◽  
Author(s):  
Xintai Xie ◽  
Thitiporn Machikowa ◽  
Sodchol Wonprasaid
Keyword(s):  
Nutrient Balance ◽  
Balance Model ◽  
Cassava Production

scholarly journals NutSpaFHy—A Distributed Nutrient Balance Model to Predict Nutrient Export from Managed Boreal Headwater Catchments

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 808
Author(s):  
Annamari Lauren ◽  
Mingfu Guan ◽  
Aura Salmivaara ◽  
Antti Leinonen ◽  
Marjo Palviainen ◽  
...  
Keyword(s):  
Peat Soil ◽  
Nutrient Balance ◽  
National Forest Inventory ◽  
Balance Model ◽  
Nutrient Export ◽  
Forested Catchments ◽  
Spatially Distributed ◽  
Body Location ◽  
Water Courses ◽  
Harvest Techniques

Responsible forest management requires accounting for adverse environmental effects, such as increased nutrient export to water courses. We constructed a spatially-distributed nutrient balance model NutSpaFHy that extends the hydrological model SpaFHy by introducing a grid-based nutrient balance sub-model and a conceptual solute transport routine to approximate total nitrogen (N) and phosphorus (P) export to streams. NutSpaFHy uses openly-available Multi-Source National Forest Inventory data, soil maps, topographic databases, location of water bodies, and meteorological variables as input, and computes nutrient processes in monthly time-steps. NutSpaFHy contains two calibrated parameters both for N and P, which were optimized against measured N and P concentrations in runoff from twelve forested catchments distributed across Finland. NutSpaFHy was independently tested against six catchments. The model produced realistic nutrient exports. For one catchment, we simulated 25 scenarios, where clear-cuts were located differently with respect to distance to water body, location on mineral or peat soil, and on sites with different fertility. Results indicate that NutSpaFHy can be used to identify current and future nutrient export hot spots, allowing comparison of logging scenarios with variable harvesting area, location and harvest techniques, and to identify acceptable scenarios that preserve the wood supply whilst maintaining acceptable level of nutrient export.

The box-balance model: a new tool to assess fish larval survival, applied to field data on two small pelagic fish

2020 ◽  
Vol 650 ◽  
pp. 289-308 ◽  
Author(s):  
V Raya ◽  
J Salat ◽  
A Sabatés
Keyword(s):  
Field Data ◽  
Fish Larvae ◽  
Larval Growth ◽  
Warming Trend ◽  
Mortality Rates ◽  
Larval Survival ◽  
Pelagic Fish ◽  
Balance Model ◽  
Small Pelagic Fish ◽  
Mesoscale Structures

This work develops a new method, the box-balance model (BBM), to assess the role of hydrodynamic structures in the survival of fish larvae. The BBM was applied in the northwest Mediterranean to field data, on 2 small pelagic fish species whose larvae coexist in summer: Engraulis encrasicolus, a dominant species, and Sardinella aurita, which is expanding northwards in relation to sea warming. The BBM allows one to quantify the contribution of circulation, with significant mesoscale activity, to the survival of fish larvae, clearly separating the effect of transport from biological factors. It is based on comparing the larval abundances at age found in local target areas, associated with the mesoscale structures (boxes), to those predicted by the overall mortality rate of the population in the region. The application of the BBM reveals that dispersion/retention by hydrodynamic structures favours the survival of E. encrasicolus larvae. In addition, since larval growth and mortality rates of the species are required parameters for application of the BBM, we present their estimates for S. aurita in the region for the first time. Although growth and mortality rates found for S. aurita are both higher than for E. encrasicolus, their combined effect confers a lower survival to S. aurita larvae. Thus, although the warming trend in the region would contribute to the expansion of the fast-growing species S. aurita, we can confirm that E. encrasicolus is well established, with a better adapted survival strategy.

Agroforestry in Eastern Otago: results from two long-term experiments

2000 ◽  
pp. 93-98
Author(s):  
G.G. Cossens ◽  
M.F. Hawke
Keyword(s):  
Soil Ph ◽  
Tree Growth ◽  
Pinus Radiata ◽  
Carrying Capacity ◽  
Livestock Grazing ◽  
Tree Age ◽  
Rapid Decline ◽  
Pasture Production ◽  
Clover Content ◽  
Pasture Yield

During the first 20 years of a Pinus radiata tree rotation, tree growth and pasture yield were assessed under a range of tree spacings at Invermay and Akatore, two coastal sites in Eastern Otago. Pasture yield in association with trees thinned to 100 stems per hectare (sph) was comparable to that from open pasture up to a tree age of 12 years. By the 19th year, however, pasture production declined to 63% of open pasture yield at Invermay and to 42% at Akatore. At 200 and 400 sph at Akatore, pasture yield was similar to that from open pasture at tree age 12 years but declined to 27% and 0% of open pasture yield respectively by year 20. At both Invermay and Akatore, the ryegrass and clover content of open pasture was relatively constant throughout the term of the trial. However, both the ryegrass and clover content of pasture beneath trees began to decline by tree age 12 years with a very rapid decline at Akatore in the number of pasture species at 200 sph by the 19th year. No pasture remained at 400 sph, after 19 years. Livestock carrying capacity with sheep on tree treatments at Invermay decreased from 100% of open pasture at year 6 to 60% by year 10. At Akatore, livestock carrying capacity averaged over the 20-year life of the trial was 4.1 stock units per hectare with a maximum of 8.1 stock units at a tree age of 8 years. Tree growth at both sites was similar, averaging between 1 and 1.1 m/year in height over 20 years, with trees at Invermay at 100 sph averaging 9% greater height and diameter growth than at Akatore. Increasing tree stocking from 100 to 200 to 400 sph at Akatore, resulted in increased tree height, but decreased diameter at breast height. A comparison of the East Otago trees with those in a similar trial at Tikitere (Rotorua) 900 km further north indicated that the southern trees were about 6 years later in their growth pattern by tree age 20 years. On both sites, soil pH tended to be lower in the presence of trees and was significantly lower than in open pasture by year 20. The results and comparisons with the Tikitere data suggest that, in an integrated agroforestry regime, there will be livestock grazing under the trees further into the tree rotation in Otago than in North Island sites. However, slower tree growth would result in a longer rotation time to harvest. Current recommendations to farmers are to plant trees on the less productive areas of the farm and adopt a tree stocking rate which fully utilises the site. Keywords: agroforestry, livestock, pasture, Pinus radiata, soil pH, tree stocking

1033 REDUCING NITROGEN FERTILIZER APPLICATIONS BY BALANCING THE NITROGEN SULFUR RATIO

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 576d-576
Author(s):  
Ellen T. Paparozzi
Keyword(s):  
Groundwater Contamination ◽  
Nitrogen Fertilizer ◽  
Nutrient Balance ◽  
Ornamental Plants ◽  
Consumer Perceptions ◽  
Consumer Acceptance ◽  
Statistical Techniques ◽  
Physiological Processes ◽  
The Impact ◽  
Future Plans

Fertilizer particularly nitrogen is part of the concern about groundwater contamination. Many floricultural and ornamental plants do not need the high rates of nitrogen that are typically recommended. However, whenever one alters the quantity of a given nutrient the overall nutrient balance, as well as other physiological processes, changes. A brief overview of our research on poinsettias, roses, and chrysanthemums will be presented. Suggested ratios, critical S levels and nutrient problems associated with incorrect balances will be shared. Limitations due to statistical methods and the impact nutrient balance has on certain plant processes such as flowering and coloring and thus, consumer acceptance will be summarized. Future plans in this area may focus on the need for new statistical techniques, nutrient acquisition by roots and consumer perceptions of plant quality.

Sign in / Sign up

Export Citation Format

Share Document