Advanced Materials Research Vols. 610-613

Abstract: Waterlogged land characterized by low productivity impact the productivity of the adjacent land and increase soil erosion. Gangzhongwa, one type of waterlogged lands, is widely distributed in Jiusan cultivated lands in Heilongjiang province China. Observation of soil profiles and measurements of soil physical properties were carried to investigate the factors related to the waterlogged land formation. The results showed Gangzhongwa waterlogged land is formed due to three reasons: firstly, the water table of groundwater is shallow and the soil profile texture varies regularly from clay loam layer, and sandy loam layer to aquitard layer; secondly soil infiltration is significantly correlated with sand content and gravel content; and thirdly the subsurface runoff makes the soil profile saturated where the surface clay loam layer is thin but the sandy layer is thick with larger infiltration rates. This study presents some theoretical insights for the Gangzhongwa waterlogged land conservation plan.

Abstract: All quotas fertifization formula in domestic and foreign, does not have consideration correctly exchange using the soil extraneous－N quantity outside fertifization and works as the season fertilizer to the soil nutrient. Calculates low 1~5 times of use factor works as season by constructed ten kinds of fertifization pattern according to works as season surface phenomenon. This will cause assumes counter-related. That both has wasted the massive fertilizers, and becomes the most widespread surface source pollution. At present, proposed the fertilizer use factor law and the entire quota fertifization pattern after inferential reasoning strictly.Hope it becomes the necessary general equation in quota fertifization.

Abstract: The effect of different soil amendment (potassium polyacrylate; polyacrylamide;potassium humate; potassium polyacrylate+ potassium humate; polyacrylamide+ potassium humate) on soil physical and chemical properties in oat field was studied. The results showed that different soil amendments increase significantly the soil organic matter, available N, available P and available K content by 8.24%-30.22%, 7.60%-19.29%, 5.15%-29.45% and 27.86%-68.86% respectively. Soil water content at 0-60 cm depth is higher with soil amendment. But soil amendment has no effect on the soil water content at 60-100 cm soil depth. At the same time, soil amendments reduce the soil bulk density at 0-10 cm,10-20 cm, 20-40 cm and 40-60 cm depths, and they produce no obvious effect on soil bulk density at 60-100 cm depth. The proportion of > 0.25 mm soil aggregate at 0-10 cm,10-20 cm and 20-40 cm depth is increased significantly by applying soil amendment. Among five aggregate sizes (> 2 mm; 2-1 mm; 1-0.5 mm; 0.5-0.25 mm; 2 mm and 2-1 mm soil aggregates are the most. In conclusion, the mixing use of two kinds of soil amendments(potassium polyacrylate+ potassium humate and polyacrylamide+ potassium humate) is more effective for improving soil physical and chemical properties.

Abstract: Soil erodibility is the K factor in the universal soil loss equation (USLE). It is generally characterized through soil physical properties-based indices. The soil erodibility of the Upper Yangtze River basin was determined by the national second soil survey data of China. The results shown that the formula calculated K in USLE model has its limitation in the area when the soil organic matter content is bigger than 12 %. An updating relation was developed by 26 sample points’ properties data. The mean value of soil erodibility in study area is 0.0344, and the biggest value distributed in Sichan basin due to the influence of terrain. Soil erodibility in the study area distributes evenly.

Abstract: The surface water of Sanjiang Plain generally contained 0.04 to 2.50 mg L^-1 of dissolved Fe ion, while the groundwater contained 0.03 to 21.00 mg L^-1, which is relative high in comparison with other regions. The purpose of this study was to investigate the effect of dissolved Fe in the irrigation water on the adsorption of ammonium. Soil samples were collected from topsoil of a paddy field. Fe²⁺concentration in either surface water (0.70 mg L^-1) or groundwater (15.0 mg L^-1) were simulated to employ batch experiments in lab. The results show that when Fe²⁺ concentration was 0.70 mg L^-1, it might slightly increase ammonium adsorption on the albic black soil. However, when Fe²⁺ concentration increased to 15.0 mg L^-1, it may increase or decrease ammonium adsorption on the albic albic black soil, depending on ammonium concentration in the soil solution. In details, ammonium adsorption capacity decreased when ammonium concentration is less than 30.77 mg L^-1, while increased when it’s more than 30.77mg L^-1. Long-term irrigated soils with groundwater might increase content of iron oxides in the paddy soils and thus increase ammonium adsorption capacity. However, Fe²⁺ in the irrigating water might also lead to desorption and leaching of ammonium in each flooding event.

Abstract: This study focus on the influence of acid rain, single and combined contamination of La and Ce, rare earth leachate of tailings on urease and catalase activities with the methods of leaching experiment and indoor thermostatic incubation. The results indicated that acid rain and rare earth contamination caused the change of soil enzyme activities. The change of urease activity accorded with hormesis effect of rare earth; at the preliminary stage of incubation, urease activity began to heighten and reached maximum value at 10th day; after being incubated for 15 days, urease activity initiated to reduce remarkably, and continued to 30th day. Accordingly, catalase activity was inhibited, then promoted slightly, the minimum value appeared in different time incubated by different solution: 15th day (La, Ce), 10th day(La + Ce), 5th day (rare earth leachate).

Abstract: Water is a limiting factor to plant growth in the Horqin Sand Land of China. Knowledge of soil saturated hydraulic conductivity (Kfs) is of importance because Kfs influences soil evaporation and water cycling under natural/artificial conditions at various scales. Kfs at fixed dunes and shifting dunes of the Horqin Sand Land were measured in situ by the Gueph permeameter. The results indicated that (1) Kfs ranged from 0.48 to 10.25 mm/min, and showed that Kfs of fixed dunes is bigger than it at shifting dunes; (2) Kfs at fixed dunes increased with increasing soil depths, but for shifting dunes, it diminished with increasing soil depths; (3) Kfs at fixed dunes is significant negative correlation with hardness, while it significant negative correlation with hardness and organic matter content at shifting dunes.

Abstract: In order to investigate the effect of water and nitrogen (N) supply on oat N accumulation, translocation and partitioning, we used two contrasting oat varieties, the naked Baiyan 2 (Avena nuda L.) and the hulled Baiyan 7 (Avena sativa L.) as experimental material, six treatment combinations, including 2 water supply regimes, no irrigation and 3 times irrigation and 3 levels of N application was 30, 90 and 150 kg N hm-2 were set in the experiment. The result showed that: At each growth stage, the N accumulation of Baiyan 2 was significantly higher than that of Baiyan 7 (p N3 >N1.The N petitioning to grain of irrigation treatment was higher than that of no irrigation. Suitable N (N2, 90kg N hm-2) can increase grain N and also NHI increased. From the result, we can conclude that Baiyan 2 is a higher N efficiency cultivar. Irrigation increased the whole plant N accumulation and partitioning to grain.

Abstract: The vegetable utilization rate of phosphorus fertilizer in greenhouse condition was low in the season of fertilizer application, resulting in phosphorus accumulation in the top soil year after year. The risk of phosphorus loss through leaching increased under the circumstance of inappropriate watering management and fertilization. In this study, leaching experiments using columns packed with a greenhouse soil with different soil phosphorus status (low, medium and high levels) were carried out under greenhouse condition to investigate the impact of fertilizer application on phosphorus leaching from greenhouse soil. The fertilization treatments included no fertilizer [CK], organic manure and chemical fertilizer [M+NPK], organic manure [M], chemical fertilizer [NPK]. The vertical migration and leaching loss of soil phosphorus were measured. Results were as follows: (1) total phosphorus (TP) content increased with the extension of leaching time. In the low-level- and medium-level-phosphorus greenhouse soils, TP concentration in the effluent increased with the application of manure; (2) In the high-level-phosphorus greenhouse soil, phosphorus in the effluent from the treatment with the use of fertilizer was the highest TP, with accumulative leaching amount of 2.85 mg in 51 days. The leaching of phosphorus became small after 36 days of leaching experiment. Our study showed that application of manure and chemical fertilizer at proper rates according to soil phosphorus status is beneficial to reduce the leaching loss of phosphorus to the environment.

Abstract: Paper provides the results of research to determine the optimum technique of soil quality analysis in reclaimed land areas. The method involves topsoil stripping and mixed replacement techniques. The soils are sampled in different years after placement. Soil properties were analyzed. The data comes from the Wu-yang mine, Shanxi Province, China. Research has resulted in four conclusions: i) by topsoil stripping, soil fertility is nearly the same as the original soil, soil nutrients are higher in the tilth layer than in the bottom soil, and there is an upward tendency. ii) by mixed pushing, soil fertility is low and heterogeneous and needs to improve fertility. iii) changes of soil heavy metal concentrations are affected by dust and sewage and have little connection with reclaimed techniques and years after reclamation. iv) reclamation by topsoil stripping is better in the plain areas. Paper discusses how to choose the best reclamation technique and decide on the recovery time of land fertility.