Erosion control of Chinese loess using polymer SH and ryegrass

The China Loess Plateau is subjected to severe soil erosion triggered by intense rainfall,resulting in significant harm and losses to both human society and the natural surroundings.In this study,a novel technique for managing loess erosion is introduced,which involves the utilization of a combined polymer SH and ryegrass.A comprehensive series of tests were undertaken,including rainfall erosion tests,disintegration experiments,and scanning electron microscopy examinations,to assess the accumulative sediment yield(ASY),disintegration ratio,and microstructural features of both untreated and treated loess samples.The results showed a significant reduction in ASY with increased dry density of untreated loess.Furthermore,the combined technique effectively controlled erosion,limiting ASY to 266.2 g/cm^(2)in 60 minutes.This was approximately one-sixth,one-ninth,and one-fifteenth of the ASY in SH-treated loess(L-SH),ryegrass-treated loess(L-R),and untreated loess,respectively.It resisted disintegration better than ryegrass alone but slightly less than SH.This improvement was due to the combined effect of SH and ryegrass,which reduced raindrop impact,improved loess microstructure,and boosted ryegrass growth.The innovative technique holds the potential to be applied as a field-scale technique in the Loess Plateau region of China.

Physiological and Biochemical Responses of Perennial Ryegrass Mixed Planting with Legumes under Heavy Metal Pollution

In artificially controlled pot experiments,perennial ryegrass was mixed with other leguminous plants(white clo-ver and alfalfa)and treated with lead,zinc and cadmium(337 mg·kg^(-1),648 mg·kg^(-1),and 9 mg·kg^(-1),respectively)to simulate compound pollution conditions.The results showed that the concentrations of heavy metals,trans-port factors,and bioconcentration factors in mixed planting of ryegrass decreased compared with those in mono-culture.Regardless of whether heavy metal pollution was introduced,mixed planting increased the aboveground and underground biomasses of ryegrass.The different mixed planting treatments had no significant impact on the chlorophyll concentration of ryegrass.The mowing time,mixed planting treatment,and heavy metal treatment had impacts on antioxidant and osmotic adjustment substances,and there were some interactions.The mixed planting treatment did not significantly affect glutathione concentration,cysteine concentration,or nonprotein thiol.Mixed planting generally increased the nitrogen and phosphorus concentrations of ryegrass while reducing the stoichiometric ratio of carbon,nitrogen,and phosphorus.These results suggest that the mixed planting of ryegrass with legumes promotes the growth of ryegrass in the presence of high concentrations of heavy metal pollution.However,it does not enhance the ability of ryegrass to remediate heavy metal pollution in the soil.

Fragipan Horizon Changes Using Annual Ryegrass and Other Admendments

A greenhouse experiment was conducted involving intact fragipan soil cores of 50 cm thickness after removing the topsoil horizons. The cores were maintained in moist condition throughout the experiment and received several treatments with various amendments for different periods ranging from 9 to 17 months. The amendments included annual ryegrass or Festulolium residues, powder limestone and various humate compounds alone or in combination with the grass residues. The results suggested a significant effect of ryegrass and Festulolium in reducing penetration resistance into the top 10 cm of the fragipan within 9 - 17 months, particularly when used in combination with certain humate materials such as Leonardite. Apparently, this is the result of the release of certain soluble organic compounds from the plant residues or the humate amendments that increase the solubility of Si and Al associated with the fragipan brittleness, thus decreasing the density of the compacted fragipan material.

The Application of Fertilizer and AMF Promotes Growth and Reduces the Cadmium and Lead Contents of Ryegrass (Lolium multiflorum L.) in a Copper Mining Area

Heavy metal-polluted soil was collected from the Pulang copper mine in Shangri-La City,Yunnan Province,Southwest China.The effects of fertilizer(organic and inorganic)and arbuscular mycorrhizal fungi(AMF)on ryegrass(Lolium multiflorum L.)growth,root morphology,mineral nutrition and cadmium(Cd)and lead(Pb)contents were investigated by pot experiments.The results showed that both fertilizer and AMF significantly ameliorated the root morphology and mineral nutrition,reduced the Cd and Pb contents,and promoted the growth of ryegrass.Among all treatments,the combined application of organic–inorganic compound fertilizer with AMF had the highest effect,resulting in increases in root length,surface area and branch number by 2.3,1.1,and 3.9 times,respectively;an 88%increase in plant biomass;a nitrogen content increase of 2.3 and 1.2 times,and phosphorus content increase of 62%and 68%in shoots and roots,respectively was also recorded as well as decreases in Cd content by 34%and 62%and Pb content by 47%and 34%in shoots and roots,respectively.Twofactor analysis showed that both fertilizer and AMF significantly promoted ryegrass growth(plant height,biomass,chlorophyll content,root length,nitrogen and phosphorus content)and reduced the Cd and Pb contents in roots,and there was a synergistic effect between them.Moreover,the nitrogen and phosphorus contents were very significantly positively correlated with the shoot and root biomasses but very significantly negatively correlated with the Cd and Pb contents of ryegrass.Thus,the application of fertilizer and AMF synergistically improved ryegrass growth on polluted soils in the copper mining area.

Callus Induction and Plant Regeneration from Mature Seeds of Perennial Ryegrass

Objective The aim was to explore callus induction and plant regeneration of perennial ryegrass, as well as provide the foundation for transgenic research on perennial ryegrass.[ Methed] Mature seeds of perennial ryegrass were used as explants to study the effects of different hormone compositions on callus induction, proliferation and plant differentiation. Result The result showed that the induction rate achieved its highest on 2,4-D of 8 mg/L combining with 6-BA of 0.025 mg/L, which was up to 56.42%. Callus were differentiated after two to three generations, the highest differentiation rate 34.14% was achieved in the medium contained MS medium with 6-BA of 2 mg/L, and the differentiation rate was obviously affected by the callus condition after proliferation. The root inducing medium, containing 0.5 mg/L NAA and MS medium with half of macroelement, gained 98% root inducing rate. Conclusien A high frequency genetic regeneration system was established.

Study on the Degradation Trend of Ryegrass-White Clover Artificial Grassland

[Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass （Lolium perenne） - white clover （ Trifolium repens） artificial grassland in Maiping Township, Guizhou Province as the research object, the grassland vegetation of 40 quadrate from different areas （area around the sheep shed, hilltop, hillside, flatland at the foot of the hill） were analyzed by comparing the dominance and richness index. [ Result] Degradation of different degrees appeared in various areas of this artificial grassland. To be specific, the degradation of grassland around the sheep shed was not serious for less consumption by the sheep; however, the areas on the hilltop and hillside degenerated to the grassland types of dallis grass （ Paspalum dilatatum Poir. ） -Indian lovegrass （ Eragrostis pilosa） and dallis grass - cogongrass [ Imperata cylindrica （ Linn. ） Beauv. ], respectively, and the area at the foot of the hill degenerated to the grassland type dominated by garland chrysanthetnum （ Chrysanthemum coronarium L. ） and knotgrass （ Paspalum distichum L. ）. [ Conclusion ] This study provided a basis for grassland improvement as well as the efficient and sustainable utilization of grazing-type artificial grassland in South China.

Effect of Ryegrasses on Soil Runoff and Sediment Control

Living plants and plant roots can reduce runoff and soil erosion. Using a rain simulator, a series of soil erosion experiments were conducted to study the influence of living roots and canopies of ryegrasses （Lolium perenne L.） during the growing season on sediment yields and runoff of a silt loam soil. The results indicated that during the growing season, decrements in runoff and sediment yields increased with time. Sediment yields （τ^2 = 0.999） and decrements in runoff （τ2 = 0.946） were closely related to the root surface area density. The contributions of roots and canopies of ryegrasses to the reductions in runoff and sediment yields were different. Canopies usually contributed more to the runoff decrement than the roots, whereas roots contributed up to 96% of the decrease in sediment yields in the late stage of the growing season.

Effects of Zn Stress on Zn Accumulation and Anti-Oxidant Enzymes Activity in Four Varieties of Ryegrass

We investigated the influence of different content of Zn^2＋（0, 2, 4, 8, 16 mmol·kg^-1） on plant growth, activities of peroxidase （POD） and superoxide dismutase （SOD）, free proline content and Zn accumulation in four varieties of ryegrass （Loliurn perenne L.） hy pot cuhure experiment. The results showed that plant hiomass increased at the ranges of 0-2 （Tuoya）, 0-4 （Yey- ing）, 0-8 mmol·kg^-1（Airuisi and Taide）, respectively, and then decreased under excess Zn. The activities of POD ,SOD and proline content in shoots decreased firstly, and then increased with the in crease of Zn content. The plaut biomass, activities of POD and SOD in Taide were evidently higher than in the other three varie ties. Root tolerance index （RTI） and Zn transport ratio from root to shoot （S/R） in Taide were exceed 1. 0. The maximum of Zn content was 583.9 mg/kg （ at 16 mmol·kg^-1） in Taide＇s shoot.

Root Exudates, Rhizosphere Zn Fractions, and Zn Accumulation of Ryegrass at Different Soil Zn Levels

A glasshouse experiment was conducted using a root-bag technique to study the root exudates, rhizosphere Zn fractions, and Zn concentrations and accumulations of two ryegrass cultivars （Lolium perenne L. cvs. Airs and Tede） at different soil Zn levels （0, 2, 4, 8, and 16 mmol kg^-1 soil）. Results indicated that plant growth of the two cultivars was not advérsely affected at soil Zn level ≤ 8 mmol kg^-1. Plants accumulated more Zn as soil Zn levels increased, and Zn concentrations of shoots were about 540 μg g^-1 in Aris and 583.9 μg g^-1 in Tede in response to 16 mmol Zn kg^-1 soil. Zn ratios of shoots to roots across the soil Zn levels were higher in Tede than in Airs, corresponding with higher rhizosphere available Zn fractions （exchangeable, bound to manganese oxides, and bound to organic matter） in Airs than in Tede. Low-molecular-weight （LMW） organic acids （oxalic, tartaric, malic, and succinic acids） and amino acids （proline, threonine, glutamic acid, and aspartic acid, etc.） were detected in root exudates, and the concentrations of LMW organic acids and amino acids increased with addition of 4 mmol Zn kg^-1 soil compared with zero Zn addition. Higher rhizosphere concentrations of oxalic acid, glutamic acid, alanine, phenylalanine, leucine, and proline in Tede than in Airs likely resulted in increased Zn uptake from the soil by Tede than by Airs. The results suggested that genotypic differences in Zn accumulations were mainly because of different root exudates and rhizosphere Zn fractions.

Revegetation of Copper Mine Tailings with Ryegrass and Willow

To restore vegetation on metal mine tailings is very difficult because theyoften contain high concentrations of heavy metals, low nutrient content and low water retentioncapacity. This study involved 3 experiments that evaluated the effects of 4 treatment amendments:montmorillonite, rice straw, organic manure and chemical fertilizer on the growth of ryegrass(Lolium perenne L.) and willow (Salix viminalis L.) with Cu and Zn mine tailings from two miningareas. The results showed that ryegrass was the most tolerant of 4 crops to Cu toxicity. Also whenorganic manure, which contained high concentrations of inorganic salts, was added to the minetailings, it significantly hindered ryegrass growth (P = 0.05). Meanwhile, with ryegrass organicmanure significantly increased (P = 0.05) the extractable Cu concentration in both mine tailings.When montmorillonite was used as a mine tailings amendment with willow, the height and tress numberat the 1st cut were significantly greater (P = 0.05) than a control without montmorillonite. Howeverthere was no significant difference for height, tress number, dry weight or root dry weight at the2nd cut. So, amendment applications to reduce metal toxicity and increase nutrients retention inmine tailings were essential during revegetation of mine tailings.

Effect of Different Amendments on Ryegrass Growth in Copper Mine Tailings

Montmorillonite, rice straw, organic manure and chemical fertilizer were usedas amendment materials for copper mine tailings, and their effects on mine tailing pH, nutrientsarid metal availability to ryegrass were investigated. Chemical fertilization was the most effectiveone in improving ryegrass growth in mine tailings among the amendment materials examined. It wasfound that montmorillonite raised biomass of ryegrass at the 1st and 2nd cuts, but it did not givefurther positive effects at the3rd and 4th cuts. The effect of organic materials on ryegrass growthwas not so good as expected, mainly due to their slow decomposition in mine tailings with less soilmicroorganisms. Available Cu and Zn contents in mine tailings decreased in the presence ofmontmorillonite but increased when rice straw and organic manure were used as amendments. Cu and Zncontents in ryegrass decreased with increasing the rate of montmorillonite application but increasedwith the rate of rice straw. Zn showed much stronger mobility from soil lo ryegrass than Cu, andalmost all the available N and P in mine tailings, except for the treatments with organic manure,were completely consumed after ryegrass had grown in mine tailings for more than four months andbeen harvested for four times. Owing to its large biomass and high metal uptake, ryegrass is apotential plant for remediation of metal contaminated soils in practice.

Effect of NPK Application on Yield,Nutrients and Water Utilization Under Sudangrass and Ryegrass Rotation Regime

Sudangrass and ryegrass rotation is a new type of cropping system in Jianghan Plain,which develops very fast in recent years.So,it is essential to work out the optimal nutrients and water management measures in this new system.The effect of NPK fertilizer on yield of forage grass,nutrients and water utilization under sudangrass and ryegrass rotation was studied through continuous pot experiments for three years.The results showed that NPK combination could significantly improve the yield of forage grasses.The total yields during the periods of 2005-2006,2006-2007 and 2007-2008 were 1 690.0,2 091.3 and 1 770.7 g/pot,respectively.The yields in PK treatment were 700.7,1 256.9 and 856.3% lower than those of NPK treatment,while the yields in NK treatment were 426.3,384.9 and 792.3% lower than those of NPK treatment,respectively.Similarly,the yields in NP treatment were 15.9,4.4 and 10.6% lower than those of NPK treatment,respectively.The NPK combination was found to improve the nutrients uptake,and the total N uptakes during the above periods were 10.0,14.8 and 10.6 times higher than that of PK treatment,respectively,and 3.7,1.8 and 5.1 times higher than those of NK treatment,respectively,but,were similar to NP treatment.The total P uptakes were 4.6,6.8 and 5.3 times higher than those of PK treatment,and were 2.4,2.3 and 2.9 times higher than those of NK treatment,respectively,but were similar to NP treatment.The total K uptakes were 5.2,8.4 and 4.9 times higher than that of PK treatment,3.9,2.3 and 3.9 times higher than those of NK treatment,and 80.9,57.4 and 200.5% higher than those of NP treatment,respectively.Water productivity for three years time periods were 16.5,16.1 and 16.2 kg m-3,and were 3.8,5.4 and 4.2 times higher than those of PK treatment,2.3,1.3 and 2.6 times higher than those of NK treatment,and were 16.4,8.8 and 22.4% higher than those of NP treatment,respectively.The soil pH was decreased and soil organic matter was increased in all treatments with increase in the time of sudangrass and ryegrass rotation system.The total soil N was increased in NP,NK and NPK treatments,while it was stable in PK treatment.The available P in NP,PK and NPK treatments was increased significantly,while it was stable in NK treatment.The slow releasing K and available K were increased significantly in NK and PK treatments,but decreased in NP and NPK treatments.The treatment with NPK combination was found to improve the yield of forage,nutrient uptake and soil fertility in sudangrass and ryegrass rotation system.

Responses of Ryegrass(Lolium perenne L.) Grown in Mudflats to Sewage Sludge Amendment

Sewage sludge amendment （SSA） is an alternative waste disposal technique and a potential way to increase fertility of mudflats for crop growth. The present study aimed to assess the suitability of SSA by assessing the nitrogen （N） and phosphorous （P） uptakes, heavy metal accumulation, growth, biomass, and yield response of ryegrass （Lolium perenne L.） at 0, 30, 75, 150, and 300 t ha-1 SSA rates at various growth stages. The results showed that the highest biomass ofryegrass at seedling and vegetative stages were at 300 and 150 t ha-1 SSA rate, respectively. The increments of ryegrass yield at reproductive stage at 30, 75, 150, and 300 t ha1 SSA rates were 98.0, 122.6, 88.1, and 61.2%, compared to unamended soil. N and P concentrations in ryegrass increased with increasing SSA rates at all stages except N and P in roots dropped significantly at 300 t ha-1 rate at vegetative stage. The metal concentration for Mn, Cu, Zn, Ni, Cd, Cr, and Pb in shoot of ryegrass at 300 t ha-1 S SA rate increased by 0.63-, 2.34-, 15.02-, 0.97-, 10.00-, 0.01- and 1.13-fold, respectively, compared to unamended soil. However, heavy metal concentrations in shoot of ryegrass were lower than the standard for forage products in China. The study suggested that sewage sludge amendment in mudflat soils might be feasible. However, the impacts of sludge application on edible crop plants and soil environment need further investigations.

Scarabaeid Larvae- and Herbicide-Resistant Transgenic Perennial Ryegrass (Lolium perenne L.) Obtained by Agrobacterium tumefaciens-Mediated Transformation of cry8Ca2, cry8Ga and bar Genes

Insect pest and weeds are two major problems for forage and turf grasses. In this study, scarab larvae- and herbicide-resistant transgenic perennial ryegrass （Lolium perenne L.） was obtained by transforming it with cry and bar genes simultaneously via the Agrobacterium-mediated method. To optimize the callus induction and plant regeneration conditions, various concentrations of 2,4-dichlorophenoxyacetic acid and 6-benzylaminopurine were assayed. The transformation efficiencies of different Agrobacterium suspension media, used during Agrobacterium-mediated transformation, were compared. Then, plasmids of pCAMBIA3301 containing cry gene （cry8Ca2 or cry8Ga） and bar gene, driven by ubiquitin promoter, were transformed into perennial ryegrass. The transformants were generated and confirmed by both Southern hybridization analysis and Western hybridization analysis. Further, the resistance of transgenic perennial ryegrass plants to scarab larvae and herbicide were analyzed. After 30 d of co-cultivation with scarab larvae, the damage to the root system of transgenic plants was less than that of non-transgenic control plants. Additionally, the leaves of transgenic plants were resistant to Basta, while leaves of the wild plants wilted after Basta spraying. These results show that cry gene and bar gene were successfully transferred into perennial ryegrass by the Agrobactgerium-mediated method, and convey resistance to scarab larvae and herbicide in transgenic perennial ryegrass plants.

Effects of EDTA and DTPA on Lead and Zinc Accumulation of Ryegrass

The tailing ponds of lead-zinc mines are artificial environment pollution sources, and also important dangerous sources of heavy metal contamination in lead-zinc mining areas. To study the effects of Ethylene Diamine Tetracetic Acid (EDTA) and Diethylene Triamine Penlaacetic Acid (DTPA) on phytoremediation of lead-zinc mining area soil, two chelators (EDTA and DTPA) were used in enrichment plant ryegrass to improve the uptake of Pb and Zn from soil. The results showed that when the doses of 0, 0.5, 1 and 2 mmol/kg EDTA and DTPA were used, the biomass of ryegrass (Lolium multiflorum Lam.) and its nutrient (N, P, K, Ca and Mg) content increased, whereas EDTA and DTPA with a dose of 4 mmol/kg decreased the biomass of ryegrass and its nutrient (N, P, K, Ca and Mg) content. EDTA and DTPA significantly enhanced the contents of Zn and Pb in ryegrass as compared with the control. As for Pb, the content of Pb in root and shoot reached a maximum of 2730.54 and 2484.42 mg/kg respectively when the dose of EDTA and DTPA was 2 mmol/kg. In the case of Zn, the content of Zn in root and shoot reached a maximum of 2428.37 and 2010.43 mg/kg respectively. The total Pb and Zn accumulations and translocation ratio in ryegrass had also been enhanced. The results indicated that EDTA and DTPA had great potential to be used for ryegrass to remedy Pb and Zn contamination soil of lead-zinc mining area, but should be used cautiously because of their environmental risks.

Content of Nutritional Elements in Sudangrass and Ryegrass Determined by ICP-AES

The sudangrass(Sorghumsudanense) and ryegrass(Lolium multiflorum L.) rotation is a newtype of cropping system,which has developed rapidly in recent years in the south of China.The contents ofnutritional elements for forage grass in the sudangrass and ryegrass rotation system were determined by ICP-AES.The results showed that there were abundant and essential nutritional elements for ani mals in sudangrassand ryegrass.The contents of P,K,Ca,Mg,S,Fe,B,Cu,Zn and Mn for sudangrass were 0.20 %～0.29 %,1.94 %～2.57 %,0.62 %～0.97 %,0.39 %～0.69 %,0.12 %～0.18 %,108.35 ～180.12,3.04 ～5.96,6.17 ～10.02,20.37 ～31.36 and 46.80 ～101.29 mg.kg-1,respectively.The contents of P,K,Ca,Mg,S,Fe,B,Cu,Zn,Mn for ryegrass were 0.39 %～0.70 %,3.77 %～5.07 %,0.61 %～0.84 %,0.28 %～0.47 %,0.32 %～0.41 %,291.65 ～632.20,2.13 ～3.23,13.29 ～15.19,30.73 ～42.98 and 92.08 ～156.04 mg.kg-1,respectively,and there were differences between various periods in nutritional elements inthe two forage grasses.The application of ICP-AES could reflect fast and efficiently the content of nutritionalelements for forage grass as ani mals feed.

Italian Ryegrass (Lolium perenne ssp. multiflorum) and Corn (Zea mays) Competition

Italian ryegrass is an annual/biennial grass that is typically used as a pasture crop or a cover crop along roadsides, rights-of-way, and industrial areas. Glyphosate-resistant (GR) Italian ryegrass populations have been documented around the world, mostly in orchard and vineyard situations. The first evidence of evolved GR Italian ryegrass in row/agronomic crops was reported from Washington County, Mississippi in 2005. GR Italian ryegrass populations can jeopardize preplant burndown options in reduced-tillage crop production systems, thereby, delaying planting operations. The effects of competition of Italian ryegrass on crop growth and yield are poorly understood. A field study was conducted in the 2012 growing season and repeated in the 2013 growing season. GR and susceptible (GS) Italian ryegrass populations were established in the greenhouse and transplanted in prepared corn row beds in the fall of 2011 and 2012 at 0, 1, 2, 3, and 4 plants·meter> of crop row. Italian ryegrass plants overwintered and developed over the following spring-summer. Glyphosate was applied at 1.26 kg·ae/ha (1.5× of labeled rate) in the spring to burndown the Italian ryegrass plants and corn was planted into the ryegrass residue 2 - 3 wk later. Current corn production practices were followed. Corn density (early and late season), height (early season), and yield and Italian ryegrass biomass (early-mid season) measurements were recorded during both years. Corn height was greater in 2012 than that in 2013 at comparable stages of the growing season, due to a cooler and wetter early season in 2013 than that in 2012. Averaged across weed densities, corn density (both early and late season) and yield were higher in the GS than those in the GR population, but Italian ryegrass biomass was similar for both populations. Averaged across Italian ryegrass populations, corn density (both early and late season), and yield were inversely proportional to Italian ryegrass density. In summary, Italian ryegrass significantly reduced corn density and yield and reduction was greater with the GR than that with the GS population. Studies are underway to study inter population competition in Italian ryegrass and investigate allelopathic effects of Italian ryegrass on selected crops.

Hyperspectral Imaging for Differentiating Glyphosate-Resistant and Glyphosate-Susceptible Italian Ryegrass

Glyphosate is widely used in row crop weed control programs of glyphosate-resistant (GR) crops. With the accumulation of glyphosate use, several weeds have evolved resistance to glyphosate. In order to control GR weeds for profitable crop production, it is critical to first identify them in crop fields. Conventional method for identifying GR weeds is destructive, tedious and labor-intensive. This study developed hyperspectral imaging for rapid sensing of Italian ryegrass (Lolium perenne ssp. multiflorum) plants to determine if each plant is GR or glyphosate-susceptible (GS). In image analysis, a set of sensitive spectral bands was determined using a forward selection algorithm by optimizing the area under the receiver operating characteristic between GR and GS plants. Then, the dimensionality of selected bands was reduced using linear discriminant analysis. At the end the maximum likelihood classification was conducted for plant sample differentiation of GR Italian ryegrass from GS ones. The results indicated that the overall classification accuracy is between 75% and 80%. Although the accuracy is lower than the classification of Palmer amaranth (Amaranthus palmeri S. Wats.) in our previous study, this study provides a rapid, non-destructive approach to differentiate between GR and GS Italian ryegrass for improved site-specific weed management.

Effects of Planting Pattern and Meteorological Factors on Yield of Ryegrass Planted in Fallow Fields

The aim was to research effects of meteorological factors on yield of ryegrass in fal ow field in winter. [Method] With grass yield as a dependent variable, effects of meteorological factors on ryegrass yield were explored by differ-ent planting methods. [Result] The yield of Zuanshi T was higher than that of Tegao; strip sowing performed better compared with dispersedly sowing and plough-ing better than no-til age; extremely high and low temperatures showed negative correlation with grass yield; higher daily average temperature, rainfal and sunshine hour improved grass yield; relative humidity and frost-free period had insignificant effects on yield. [Conclusion] The region with less extreme temperatures should be chosen as the site for growing ryegrass.

Impact of Annual Ryegrass on Nitrate-N Losses during One Growing Season of Maize in the Midwestern United States <br/>—An On-Farm Case Study

Winter cover crops have been shown to reduce nitrate-N (NO3-N) losses in runoff water and are recommended by the Illinois Nutrient Loss Reduction Strategy (NLRS) for reducing nutrient losses from agricultural fields. With an estimated 80 percent of the NO3-N load in Illinois coming from agriculture, the NLRS stresses the importance of farmers’ voluntary implementation of best management strategies in order to reach these goals. This study compares the difference in NO3-N losses from tile drainage water from an annual ryegrass (AR, Lolium multiflorum) winter cover-cropped treatment to a conventional tillage (CT) control (fall chisel and spring field cultivation). Throughout the maize (Zea mays L.) growing season, tile drainage water was collected and analyzed for NO3-N concentrations. Despite the AR treatment having a 29% lower mean daily NO3-N concentration, there was no significant difference in total daily NO3-N flux between AR and CT for this study period of April-July 2015. The cumulative losses of NO3-N were calculated at 11.65 and 10.56 kg ha?1 NO3-N for the CT and AR treatment, respectively, or a 9.4% reduction in the AR treatment during the period of study. When the season was divided based on growing season periods, the NO3-N flux values were less for the cover crop while the AR was actively growing, greater for the cover crop for the period following annual ryegrass termination through maximum crop canopy, and lower for the cover crop in the late stages of vegetative growth through relative maturity.