Studies On The Effect Of Nitrogen Forms And Nitrogen Proportion On Growth And Development Of Blueberry

The effect of nitrogen forms and nitrogen proportion on the change of soil pH,plant growth, physiological guide line of leaves, fruit quality, fruit yield were studied,utilizing fertilization on field and tissue culture technique on highbush blueberry'Bluecrop'. It has the important theoretical and practical significance in studying theblueberry nitrogen forms and nitrogen proportion which is helpful to establishment ofgood quality,high and steady output blueberry orchard. The main results were asfollows:1. Nitrogen forms were influenced to soil pH in two years applied nitrogen.Ammonium nitrogen obviously decreased soil pH, range of changes were 0.73-1.21;Urea nitrogen also decreased soil pH, range of little changes were 0.24-0.54; Ascompared to ck, nitrate nitrogen increased soil pH range of changes were 0.29-0.78.It increased soil pH in ammonium nitrogen added to nitrate nitrogen.2. That ammonium nitrogen were better. Shoot length, ground shoot length, areaof leaves and content of chlorophyll which was 1.059 mg·g^-1 had augmented,Photosynthesis had increased. Organic content which were fusibility total sugar andfusibility total protein had accumulated. POD activity of leaves and NR activity ofleaves had decreased. Showed that blueberry leaves metabolize greater activity,accelerated procreation growth that improved proportion of inserted fruit, so yield ofbush had increased and quality of blueberry which increased Vitamin C, content ofsoluble sugar, color value had influenced. Secondly, it was Urea nitrogen, plantgrowth had promoted, as compared to the same of ammonium nitrogen, growth, yieldand quality of blueberry had decreased. Nitrate nitrogen was worse for blueberryabsorption and assimilation, therefore, blueberry manifested small growth, area ofleaves, little organic matter, worse yield and quality of blueberry.3. Ammonium nitrogen and urea nitrogen changed shoot length, ground shootlength, area of leaf etcaeteras character of growth showed converse 'V' change rule asnitrogen concentration changed in different nitrogen concentration treatment which in the same of nitrogen forms. Nitrogen concentration which were 30-45 gN/plantpromoted nutrition growth, more organic matter in blueberry leaves had accumulated,utilized more better sun-energy, therefore, improved proportion of inserted fruit andbetter ratio of sugar and acid. Nitrate nitrogen influenced little growth in the lownitrogen concentration, high nitrogen concentration restrained growth of blueberry,weight of a hundred berries reduced 13.56 g as compared to ck, increased acid in fruit,reduced flavor of fruit.4. That proportion of nitrogen treatment were NH₄⁺-N/NO₃^--N=5:1, 4:2 werebetter, it increased variation of plants, content of chlorophyll, Pn.. It was rationalutilized optical energy which increased fusibility total sugar and fusibility total sugar,blueberry absorption and assimilation were better. Therefore, it increased yield ofbush.5. That proportion of nitrogen treatment were NH₄⁺-N/NO₃^--N=5:5, 7:3 werebetter for blueberry plants of culture tissue in WPM, it increased content ofchlorophyll composition and accumulated fusibility total sugar and protein, so itincreased variation of plants.6. It was exact method that technique of leaf analysis was ascertained nitrogenconcentration and nitrogen forms. Showed that ammonium nitrogen and urea nitrogenincreased content of N, P, Fe, Mg, Mn in leaf, and decreased content of K, Ca. Nitratenitrogen was reverse to result.