Alfalfa stems, reed canarygrass, and switchgrass; perennial herbaceous species that have potential as biomass energy crops in temperate regions; were evaluated for their bioconversion potential as energy crops. Each forage species was harvested at two or three maturity stages and analyzed for carbohydrates, lignin, protein, lipid, organic acids, and mineral composition. The biomass samples were also evaluated for sugar yields following pretreatment with dilute sulfuric followed by enzymatic saccharification using a commercial cellulase preparation. Total carbohydrate content of the plants varied from 518 to 655 g kg � 1 dry matter (DM) and cellulose concentration from 209 to 322 g kg � 1 DM. Carbohydrate and lignin contents were lower for samples from early maturity samples compared to samples from late maturity harvests. Several important trends were observed in regards to the efficiency of sugar recovery following treatments with dilute acid and cellulase. First, a significant amount of the available carbohydrates were in the form of soluble sugars and storage carbohydrates (4.3–16.3% wt/wt). Recovery of soluble sugars following dilute acid pretreatment was problematic, especially that of fructose. Fructose was found to be extremely labile to the dilute acid pretreatments. Second, the efficiency at which available glucose was recovered was inversely correlated to maturity and lignin content. However, total glucose yields were higher for the later maturities because of higher cellulose contents compared to the earlier maturity samples. Finally, cell wall polysaccharides, as determined by the widely applied detergent fiber system were found to be inaccurate. The detergent fiber method consistently overestimated cellulose and hemicellulose and underestimated lignin by substantial amounts. Published by Elsevier Ltd.

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Chemical composition and response to dilute-acid pretreatment and enzymatic saccharification of alfalfa, reed canarygrass, and switchgrass

Invasive species pose a serious threat to native plant communities and are an important contributor to loss of biodiversity. In the case of Phalaris arundinacea, L. (Poaceae), reed canary grass, a cool-season, long-lived perennial plant native to Eurasia and North America, nonnative agronomically important genotypes were introduced to North America for numerous uses such as forage and soil stabilization. Following repeated introductions, reed canary grass became an aggressive invader that takes over natural wet prairies, stream-banks and wetlands. Reed canary grass can outcompete native plant species, resulting in monospecific stands with concomitant loss of plant and insect diversity and ultimately to alteration in ecosystem function. Abiotic factors such as disturbance, changes in hydrological regime, and particularly nutrient runoff to wetlands can enhance reed canary grass establishment and vegetative spread. In addition, the species' capacity for early season growth, rapid vegetative spread, high ste...

Reed Canary Grass (Phalaris arundinacea) as a Biological Model in the Study of Plant Invasions

Growth of Phragmites australis and Phalaris arundinacea in constructed wetlands for wastewater treatment in the Czech Republic

van der Hoek. 2002. Wastewater use in agriculture: Review of impacts and methodological issues in valuing impacts. (With an extended list of bibliographical references). Working Paper 37. Colombo, Sri Lanka: International Water Management Institute. / wastewater / water management / water quality / groundwater recharge / water reuse / cost benefit analysis / agricultural production / domestic water / water pollution / public health / economic aspects / ecology / developing countries / China / India / Mexico / Pakistan / IWMI receives its principal funding from 58 governments, private foundations, and international and regional organizations known as the Consultative Group on International Agricultural Research (CGIAR).

Wastewater use in agriculture: Review of impacts and methodological issues in valuing impacts

Hydrological models featuring root water uptake usually do not include compensation mechanisms such that reductions in uptake from dry layers are compensated by an increase in uptake from wetter layers. We developed a physically based root water uptake model with an implicit compensation mechanism. Based on an expression for the matric flux potential ( M ) as a function of the distance to the root, and assuming a depth-independent value of M at the root surface, uptake per layer is shown to be a function of layer bulk M , root surface M , and a weighting factor that depends on root length density and root radius. Actual transpiration can be calculated from the sum of layer uptake rates. The proposed reduction function (PRF) was built into the SWAP model, and predictions were compared to those made with the Feddes reduction function (FRF). Simulation results were tested against data from Canada (continuous spring wheat [( Triticum aestivum L.]) and Germany (spring wheat, winter barley [ Hordeum vulgare L.], sugarbeet [ Beta vulgaris L.], winter wheat rotation). For the Canadian data, the root mean square error of prediction (RMSEP) for water content in the upper soil layers was very similar for FRF and PRF; for the deeper layers, RMSEP was smaller for PRF. For the German data, RMSEP was lower for PRF in the upper layers and was similar for both models in the deeper layers. In conclusion, but dependent on the properties of the data sets available for testing, the incorporation of the new reduction function into SWAP was successful, providing new capabilities for simulating compensated root water uptake without increasing the number of input parameters or degrading model performance.

Macroscopic Root Water Uptake Distribution Using a Matric Flux Potential Approach

Effects of Municipal Wastewater Effluent and Cutting Management on Persistence and Yield of Eight Perennial Forages1

No experimental comparisons have been reported of the yield of feed components of fodder maize (Zea mays L.) and of perennial grasses in production systems that use municipal waste water effluent. Our objective was to determine the feed quality and yields of maize fodder and reed canarygrass (Phalaris arundinacea L.) when they were managed by conventional practices and when they received municipal waste water effluent during the growing seasons over a 4-year period. Three soil treatments included a control (well water and mineral fertilizer) and two municipal waste water effluent levels (usually ≅ 5 or 10 cm/week), each applied to reed canarygrass and maize (2 × 3 factorial). In all except the first year, maize fodder was more digestible (X of 74.4%) than reed canarygrass (X of 68.9%) subjected to any soil treatment. Reed canarygrass always contained much more crude protein (X of 17.5%) than did maize (X of 7.2%). Maize fodder yielded from 17 to 36% more dry matter and from 23 to 41% more digestible dry matter per hectare than did reed canarygrass. These differences were progressively less as effluent application increased from 0 to ≅ 10 cm/week. Reed canarygrass yielded from 30 to 52% more crude protein per hectare than did maize. These differences were progressively greater as effluent application increased. We conclude that perennial grasses have superior capacity compared to maize to remove N from soil treated with large amounts of waste water effluent. The grasses are also most likely to yield the most protein per hectare, but the least digestible dry matter, in effluent-treated systems. We documented that both reed canarygrass and maize can effectively renovate large amounts of waste water effluent applied to permeable soils.

G. C. Marten

Papers

Effects of Municipal Wastewater Effluent and Cutting Management on Persistence and Yield of Eight Perennial Forages1

Effects of municipal waste water effluent on performance and feed quality of maize vs. reed canarygrass.

Effects of Municipal Wastewater Effluent and Cutting Management on Root Growth of Perennial Forage Grasses1

Maize Culture in Reed Canarygrass Sod to Renovate Municipal Wastewater Effluent1