Productivity And Nutrition Value Of The Four Grasses

This paper researched four grasses: Hordeum brevisubulatum, Roegneria turczaninovii,Bromus inermis, Elymus nutans. The development characteristics, photosynthetic characteristics, salt resistance, productivity and nutrition value of the four forage grasses were analyzed to evaluate their productive force and nutrion value. The results were as follows:1. The diurnal dynamics of photosynthetic rate (Pn) and transpiration rate (Tr) of two years planted grasses under suit environment condition, as well as those of photosynthetic active radiation (PAR), CO2 concentration in field (Ca), relative humidity (RH) and air temperature (Ta) were measured, and the relationships between the diurnal dynamics of Pn and leading factors were analyzed by correlation coefficient. The results are as follows: 1) The diurnal dynamics of photosynthetic rate (Pn) of the three species exhibited a twin-peaked pattern. The first apex of Hordeum brevisubulatum appeared at 8:00, but the first apex of Elymus nutans and Roegneria turczaninovii appeared at 10:00. The second apex of Hordeum brevisubulatum appeared at 14:00, Roegneria turczaninovii and Elymus nutans appeared at 16:00; 2) There was noon depression of photosynthesis for Hordeum brevisubulatum at 12:00. Noon depression of photosynthesis for Roegneria turczaninovii and Elymus nutans appeared 13:00; 3) For the characteristics of photosynthesis of Hordeum brevisubulatum and Elymus nutans, Gs was the leading factor, while Ci had the greatest effect on the characteristics of photosynthesis of Roegneria turczaninovii.2. The results showed that the condition of seed germination of the four grasses had a decreasing tendency of diferent degrees with the increasing of NaCl salt concentrations. Low salt concentrations have a certain stimulus to germination of seeds and radicel of Hordeum brevisubulatum and Roegneria turczaninovii. The seed of the four forage grasses presented salt tolerance to a certain extent.Salt resistance of Roegneria turczaninovii and Hordeum brevisubulatum were the highest and that of Bromus inermis was lower,Elymus nutans lowest to compare to the others.3. The yield of the four grasses were Bromus inermis (11290.1kg/hm~2)> Roegneria turczaninovii (10817.9kg/hm~2)>Elymus nutans (9298.2kg/hm~2)>Hordeum brevisubulatum (6515.2kg/hm~2). The seed production of the four forage grasses were Roegneria turczaninovii (835.04 kg/hm~2) > Bromus inermis (710.78 kg/hm~2) > Elymus nutans (702.28 kg/hm~2) > Hodeum brevisubulatum (320.34 kg/hm~2).4. The paper analysed nutrition of the four grasses. The result showed that Hordeum brevisubulatum was grasses which contained middle calcium and high phosphorus. Roegneria turczaninovii, Elymus nutans and Bromus inermis were grasses which contained low calcium and middle phosphorus. ratio of calcium and phosphorus of Hordeum brievisubulatum and Roegneria turczaninovii were in perfect range, but that of Elymus nutans and Bromus inermis were outside.5. EAAI values of the four grasses were higher than 0.95, so they were well-fed. Nutrion of Hordeum brevisubulatum and Roegneria turczaninovii in tasselling Period were higher than other periods. Nessary amino acid of Hordeum brevisubulatum and Roegneria turczaninovii in tasselling Period were equilibria. Nutrion of Elymus nutans in autum was higher than other periods. Nessary amino acid of Elymus nutans was equilibria.