Silage storage runoff characterization: Annual nutrient loading rate and first flush analysis of bunker silos

We are currently involved in a whole-lake experiment designed to assess how Daphnia affect the response of mesotrophic lakes to increased nutrient loading. In the first year of the experiment, we wished to demonstrate that there are P loading rates which eutrophy lakes without Daphnia but not lakes with Daphnia. In order to do this, we needed to choose an appropriate level and schedule for the experimental enrichment. This paper describes how we made that choice, then evaluates whether our choice was successful. Based on the literature, a simulation model, and a mesocosm experiment, we decided that enriching at a rate of 1 μg P L−1 d−1 would create the desired contrast between lakes with and without Daphnia. Model simulations indicated that mean algal response to enrichment would be comparable under monthly, weekly, or continuous additions. We chose to add nutrients continuously at ambient N:P ratios. Experimental results from 1993 suggest that we achieved a nutrient loading rate consistent with our goal: chlorophyll responded less to enrichment in the lake with Daphnia than in the lake without Daphnia. The modeling, mesocosm, and whole-lake studies summarized here support the idea that Daphnia reduce chlorophyll at P loads ≤1 μg P L−1 d−1. However, cyanobacteria may escape control by all grazers at relatively low P loading rates.

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The Sensitivity Analysis of a Lake Ecosystem with the Conditional Nonlinear Optimal Perturbation Method

Advances in Meteorology ◽

10.1155/2012/562081 ◽

2012 ◽

Vol 2012 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Bo Wang ◽

Peijun Zhang ◽

Zhenhua Huo ◽

Qianqian Qi

Keyword(s):

Nutrient Loading ◽

Loading Rate ◽

Initial Perturbation ◽

Finite Amplitude ◽

Lake Ecosystem ◽

Conditional Nonlinear Optimal Perturbation ◽

Optimal Perturbation ◽

Amplitude Parameter ◽

Nutrient Loading Rate ◽

Method Show

The instability and sensitivity of a lake ecosystem to the finite-amplitude perturbations related to the initial condition and the parameter correspondingly are studied. The CNOP-I and CNOP-P methods are adopted to investigate this nonlinear system. The numerical results with CNOP-I method show that the lake ecosystem can be nonlinearly unstable with finite-amplitude initial perturbations when the nutrient loading rate is between the two bifurcation points. A large enough finite amplitude initial perturbation, that is, CNOP-I, can induce a transition from an oligotrophic (eutrophic) state to an eutrophic (oligotrophic) state. With CNOP-P method, it is shown that the lake ecosystem can be transformed from an oligotrophic (eutrophic) state to an eutrophic (oligotrophic) state with a large enough finite amplitude parameter perturbation, that is, CNOP-P, no matter how large the nutrient loading rate is.

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The Research on the Lake Eutrophication with CNOP Method

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.599.705 ◽

2012 ◽

Vol 599 ◽

pp. 705-708 ◽

Cited By ~ 1

Author(s):

Bo Wang ◽

Zhen Hua Huo ◽

Qian Qian Qi ◽

Pei Jun Zhang

Keyword(s):

Nutrient Loading ◽

Loading Rate ◽

Initial Perturbation ◽

Finite Amplitude ◽

Lake Ecosystem ◽

Initial Condition ◽

Parameter Perturbation ◽

Conditional Nonlinear Optimal Perturbation ◽

Optimal Perturbation ◽

Nutrient Loading Rate

Using a dynamical model for nutrient cycling in shallow lakes, the approach of conditional nonlinear optimal perturbation (CNOP) was adopted to investigate the instability and the sensitivity of the lake ecosystem to finite-amplitude perturbations both related to the initial condition and the parameter. The results show that the ecosystem can be transformed from an oligotrophic (eutrophic) state to an eutrophic (oligotrophic) state with a CNOP as the perturbation, no matter how large the nutrient loading rate is. Above all, with the same restraints related to the initial perturbation and the parameter perturbation, CNOP has the largest effect on the lake ecosystem, which may be helpful to govern the lake ecosystem.

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Nutrient loading rate effects on nutrient removal in a five-step sequencing batch reactor

Process Biochemistry ◽

10.1016/s0032-9592(03)00135-3 ◽

2003 ◽

Vol 39 (4) ◽

pp. 507-512 ◽

Cited By ~ 10

Author(s):

Fikret Kargi ◽

Ahmet Uygur

Keyword(s):

Nutrient Removal ◽

Sequencing Batch Reactor ◽

Nutrient Loading ◽

Loading Rate ◽

Batch Reactor ◽

Rate Effects ◽

Nutrient Loading Rate

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Early outplanting performance of nutrient-loaded containerized black spruce seedlings inoculated withLaccaria bicolor: a bioassay study

Canadian Journal of Forest Research ◽

10.1139/x00-003 ◽

2000 ◽

Vol 30 (5) ◽

pp. 744-752 ◽

Cited By ~ 27

Author(s):

A M Quoreshi ◽

V R Timmer

Keyword(s):

Dry Matter ◽

Nutrient Loading ◽

Loading Rate ◽

Black Spruce ◽

Nutrient Content ◽

Growth Potential ◽

Combined Treatments ◽

Matter Production ◽

Light Vector ◽

Mycorrhizal Inoculation

Early growth potential of nutrient-loaded and (or) Laccaria bicolor (R. Mre.) Orton inoculated (Picea mariana (Mill.) BSP) seedlings was investigated using pot bioassays retrieved from a low-competition feathermoss site and a high competition hardwood-Alnus site in the boreal forest. Mycorrhizal seedlings were similar in biomass and shoot/root ratio to nonmycorrhizal seedlings at planting but significantly higher in nutrient content depending on fertilization regime and loading rate. After transplanting, both nutrient-loaded and inoculated seedlings outperformed conventional seedlings, increasing dry matter production by 20-49% with loading and by 45-92% with combined treatments. Nutrient uptake followed similar trends, increasing N, P, and K uptake by 80-124, 89-129, and 72-106%, respectively, for combined treatments compared with conventional seedlings, demonstrating the advantage of both nutrient loading and inoculation in early plantation establishment. Seedling response was greater on the feathermoss site, presumably because of less competition for nutrients and light. Vector diagnosis indicated the response was associated with a primary limitation of N and P that was alleviated by nutrient loading and mycorrhizal inoculation, particularly when treatments were combined. A strong correlation between preplant N content and outplant biomass suggests that initial nutritional status is a better criterion for predicting stock quality than traditional morphological parameters of seedlings.

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