Nutrients Release Characteristics Of Controlled Release Fertilizer And The Effect On Growth Of Corylus Avellana L.

Fertilizer plays an important role in agricultural production, but the lower use efficiency and a series of environmental, agricultural harm has attracted more attention. So research of slow/controlled release fertilizers has been one of the hot subjects. In this experiment, filbert as experiment material, in accordance with its domestic fertilizer characteristics of the whole growth period, special controlled-release fertilizer was mixed, nutrient release and fertilizer use efficiency were studied with laboratory experiments combined with field testing methods.In this experiment, release law of fertilizer was immersed in still water culture of 25℃and soil column leaching method, and contrasted with the common compound fertilizer and release fertilizer, investigated impact of physical characteristics, nutrient uptake and growth indicators of the mixed controlled release fertilizer, and further study on soil pH, EC, available N, available P and K content and urease, acid phosphatase and catalase enzymes of different treatments. The major findings are as follows:First,nutrient release rate increased slowly in the beginning of bulk blend controlled release fertilizer in still water of 25℃, which was the highest in the first 3th days, but it did not exceed 10%, after the period it is basically maintained at 2%. Within the 35th days, phosphorus and potassiumnutrients cumulative release rate was 28.5%, 9.31%, 27.43%. In the 35th days the rate release process of mixed controlled release fertilizer was rapid in the first, nitrogen, phosphorus and potassium release rates were 20.16%, 15.57%, 33.3%, it is basically remained at 2% in the afterstage, nutrients cumulative release rate of nitrogen, phosphorus and potassium was 49.4%, 20.8%, 40.7% in the 35th day.Second, the lowest value of eluent pH of general compound fertilizer processing was in the 70th day, the controlled release bulk blend fertilizerwas the 14th day, mixed controlled-release fertilizer was in the 63th day. Controlled-release bulk blend fertilizer and mixed controlled release fertilize of eluent EC gradually increased to a maximum value and then decreasing, and then increased, increase rate of the first 14th days to 35th days was small, it dramatically increased from 35th day to 56 day. In the 56th day to 63th day, it declined sharply and then it is minimum value and increased at last. The nitrogen, phosphorus and potassium accumulated leaching rate of common compound fertilizer is the biggest. In the 70th day, the release rate reached 52.81 %, which was higher 15.78%,20.08%, compared with net controlled release fertilizer and controlled release bulk blend fertilizer. In the 70th day, total phosphorus release rate of common compound fertilizer is 43.80 %,while accumulated phosphorus leaching rate of the controlled release fertilizer is 17.72%, the accumulated phosphorus leaching rate of the controlled-release fertilizer bulk blend fertilizer was 27.09 %. In the 70th day, total potassium release rate of common compound fertilizer is 50.30%, while accumulated potassium leaching rate of the controlled release fertilizer is 28.60%, the accumulated potassium leaching rate of the controlled-release fertilizer bulk blend fertilizer was 36.7%.Third, in the four periods of hazel growing, hazel leaf net photosynthetic rate of controlled release fertilizer increased by 6.9%-93.3% compared with common compound fertilizer, transpiration rate increased by 5.8% ~ 19.0%, stomatal conductance increased by 4.8% 27.1%, stomatal limitation value decreased 4.8%～64.5%;Compared with common compound fertilizer, hazel leaf net photosynthetic rate of controlled release fertilizer increased by9.9%～94.7% compared with common compound fertilizer, transpiration rate increased by 9.9%～94.7%, stomatal conductance increased by 4.3%～29.4%, stomatal limitation value decreased 9.3%～62.8%.Four, the available nitrogen, available phosphorus and available potassium content of controlled-release fertilizer or controlled-release fertilizer bulk blend fertilizer were higher than common fertilizer. About the soil enzymes, in the early stage the common fertilizer can maintain a high soil nutrient content and related with a high enzymes level activity, then by late growth stage nutrient content gradually decreased caused lack of nutrient; Controlled-release fertilizer can make soil fertility levels were at a high level by the whole stage; Controlled-release bulk blend fertilizer not only enriches the soil nutient at a higher level by the whole growth period, but also can effectively low the fertilizer cost. In addition, the plant NPK content of controlled release fertilizer and controlled release bulk blend fertilizer treatment was higher 20% ~30% than common fertilizer.Five, compared with no fertilizer treatment, fertilization treatment improved hazelnut leaf length, leaf width, plant height and stem diameter, including leaf length increased 0.93 ~ 1.30cm, leaf width increased 0.63 ~ 0.83cm, plant height increased 29.7 ~ 45.4cm, stem diameter increased 0.63 ~ 0.93cm. Compared with common compound fertilizer, hazelnut leaf length and leaf width was not obvious by controlled release fertilizer and controlled release bulk blend fertilizer, the difference was not significant; affected on hazelnut plant height and stem diameter was significant, including plant height increased by 9.3cm, 15.7cm, diameter increased by 0.24cm, 0.30cm.