[Application effect of high efficiency and stability urea added with biochemical inhibitors and humic acid in loess].

We carried out pot experiment to investigate nitrogen transformation characteristics, yield increasing effect, and apparent utilization rate of nitrogen fertilizer in loess soils by combining chemi-cal inhibitor and biostimulant humic acid to investigate the application effect and provide a theoretical basis for new type highly efficient and stable urea in loess soil. In this study, blank (CK) and urea (N) were set as controls, and humic acid alone (F), N-butyl thiophosphate-triamine (NBPT), 3,4-dimethyl-pyrazolate phosphate (DMPP), 2-chloro-6-trimethyl-pyridine (CP) and humic acid were respectively combined with three biochemical inhibitors to urea. The results showed that compared with N treatment, F, NBPT+F, DMPP+F, CP+F treatments significantly increased maize yield, chlorophyll content, leaf area index and nitrogen uptake, and had obvious effects on soil available nitrogen contents.

Effects of different nitrification inhibitors on nitrification, maize yield, and nitrogen use efficiency in red soil.

We examined the effects of nitrification inhibitors (NIs) on soil nitrification, maize yield and nitrogen use efficiency (NUE), aiming to screen out high efficiency stabilized ammonium chloride fertilizer in red soil. Nitrification inhibitors 2-chloro-6-trimethyl-pyridine (CP), 3, 4-dimethyl-pyrazolate phosphate (DMPP), and dicyandiamide (DCD) and their combinations were added into ammonium chloride (NHCl) to make six stabilized nitrogen fertilizers. With blank (CK) and NHCl (N) as the controls, we conducted a maize pot experiment with the same amount of nitrogen addition.

[Effect of urease/nitrification inhibitor on urea nitrogen conversion in black soil and cinnamon soil.].

We studied the effects of urease/nitrification inhibitor combinations on urea hydrolysis and nitrification, aiming to screen out the effective inhibitor combinations for black soil and cinnamon soil in Northeast China. Urease inhibitor, N-butyl thiophosphate-triamine (NBPT), and its combination with nitrification inhibitor dicyandiamide (DCD), 3, 4-dimethylpyrazole phosphate (DMPP), 2-chloro-6 (trichloromethyl)-pyridine (CP), 2-amino-4-chloro-6-methylpyrimidine (AM) and 3-methylpyrazole (MP) were added to urea separately. Samples were collected 15 times in each of all the treatments during 125 days.

[Effects of high efficiency and stability ammonium sulfate fertilizer applied in black soil].

To develop high efficiency stabilized N fertilizer, a pot experiment was conducted to examine the effects of stabilized ammonium sulfate with different nitrification inhibitors on soil avai-lable nitrogen (N) contents, nitrification inhibition rate, apparent nitrification rate, yield, some agronomic parameters and N fertilizer utilization rate of corn in black soil of Jilin Provinve. In this study, blank (CK) and (NH)SO (N) were set as controls, and nitrification inhibitor 3,4-dimethyl-pyrazolate phosphate (DMPP), 2-chloro-6-trimethyl-pyridine (CP), ammonia protectant N-GD and nitrogen fertilizer synergist HFJ and their combination applied to ammonium sulfate to form nine treatments. The results showed that compared with the treatment of N, application of DMPP and its combinations in black soil significantly affected soil available N contents and the apparent nitrification rate.

[Effects of inhibitors and pig manure on the transformation of urea nitrogen in paddy soil].

With the aim to understand the response of different nitrogen forms in paddy soil under the conditions of urea combined with inhibitors and pig manure, and to explore the nitrogen retention and supply capacity of paddy soil under different management strategy, we conducted a pot experiment with N labeled urea. There were six treatments: no nitrogen fertilizer (CK), pig manure (M), urea (N), urea+pig manure (NM), urea+inhibitor (NI), urea+inhibitor+pig manure (NIM). Urease inhibitor (PPD+NBPT) and nitrification inhibitor (DMPP) were used as the inhibitor combination.

[Effects of stabilized N fertilizer combined with straw returning on rice yield and emission of NO and CH in a paddy field].

Based on a two-year field experiment located at Shenyang Applied Ecological Experiment Station of Chinese Academy of Sciences, we examined the effects of stabilized N fertilizer combined with straw returning on rice yield and emission of NO and CH in aquic brown soil. Six treatments were set up, i.e.

[Nitrogen transformation of stable ammonium fertilizer in black soil and cinnamon soil].

A chamber culture experiment was conducted to measure soil nitrogen transformation following application of stabilized ammonium fertilizers in black soil and cinnamon soil. There were three application levels (0.20, 0.

[Characteristics of ammonia volatilization and nitrous oxide emission from a paddy soil under continuous application of different slow/controlled release urea.].

The characteristics of ammonia volatilization and nitrous oxide emission from a paddy soil were examined under 9-year application of different slow/controlled release urea with the common large granule urea (U) as the control. The results showed that compared with the control, all slow/controlled release urea treatments, except 25.8% increase of ammonia volatilization under 1% 3,4-dimethylpyrazole phosphate (DMPP)+U, could decrease the ammonia volatilization.

[Analysis of the character of film decomposition of methyl methacrylate (MMA) coated urea by infrared spectrum].

The degradability characteristics of film with 4 kinds of methyl methacrylate coated urea amended with inhibitors were analyzed by FITR, which was purposed to supply theoretical basis for applying the FITR analysis method to film decomposition and methyl methacrylate coated urea fertilizers on farming. The result showed that the chemical component, molecule structure and material form of the membrane were not changed because of adding different inhibitors to urea. the main peaks of expressing film degradation process were brought by the -C-H of CH3 & CH2, -OH, C-O, C-C, C-O-C, C=O, C=C flexing vibrancy in asymmetry and symmetry in 3 479-3 195, 2 993--2 873, 1 741-1 564, 1 461-925 and 850-650 cm(-1).

[Analysis of soil humus and components after 26 years' fertilization by infrared spectroscopy method].

The infrared spectrum was used to discuss structure change of soil humus and components of chemical groups in soil humic acids (HA) and fulvic acids (FA) isolated from soils in different fertilization treatment after 26 year's fertilization. The result indicated that using the infrared spectroscopy method for the determination of humus, humus fractions (HA and FA) and their structure is feasible. Fertilization affected the structure and content of soil humus and aromatization degree.

[Variations in IR spectra of three coating materials under outdoor illumination and pot incubation].

In the present paper, polylactic acid (PLA), poly (butylenes succinate) (PBS) and polycarbonate (PC) were selected as test coating materials, and the variations in their IR spectra under conditions of outdoor illumination and pot incubation were studied, aimed to approach the degradability of these coating materials under sunlight and in soil. The IR spectra showed that after 4 months under outdoor illumination and pot incubation with brown soil and black soil, all the test coating materials had definite variations in their structural configuration, being more obvious under pot incubation than under outdoor illumination, which suggested that the test materials were degradable, and the degradability was greater in soil than under sunlight. PC had the greatest degradability, followed by PLA, and PBS.

[A microplate fluorimetric assay for sacchariase activity measurement].

With the fluorescent compound conjugates substrates, soil xylanase and cellulose in a free-air carbon dioxide enrichment (FACE) experiment were measured on the base of 96 microplate and fluorescence detection, aiming at testing its feasibility in sacchariase activity measurement. The results show that sacchariase activity can be tested and the data exhibit better repeatability(coefficient of variability <= 4.879%).

[Impact of chemical fertilizers application on soil ecological environment].

China heads the list in the world's chemical fertilizers production and consumption. In 2006, the chemical fertilizers production in this country was 5304.8 x 10(4) t, being 14.