不同生育期水分胁迫对玉米农艺性状的影响

为了研究不同生育期玉米水分胁迫对玉米农艺性状的影响,为干旱、半干旱地区玉米抗旱提供理论依据。以玉米在苗期、拔节期、抽雄-吐丝、灌浆-成熟期进行水分胁迫,测量玉米株高、穗位高、叶面积、穗部性状,对比充分灌水与非充分灌溉下玉米农艺性状差异。利用Jensen模型求解出玉米各生育期水分敏感系数,验证水分胁迫对玉米产量的影响。结果表明在拔节期进行干旱处理的株高、穗位高、叶面积受影响较大,有明显的抑制作用。抽雄—吐丝期干旱胁迫对穗部性状的形成较为明显,并且对产量影响较大。     

大豆水溶性蛋白含量测定的不确定度评定

建立大豆水溶性蛋白含量测定（NY/T 1205-2006）不确定度评定的数学模型,对检测过程中带来的各个不确定度分量进行识别和量化,提出应用该方法检测的不确定度评定结果。     

浅谈热水锅炉的安全运行

作者依据20多年的工作实践经验,对热水锅炉安全运行的必要条件进行了较为详细的阐述。     

基于鸡西市第一中学新校区规划建设的思考

在鸡西市第一中学建设新校区的规划设计中,通过对总体布局、交通组织、场区竖向、运动场地及校园绿化等方面做详细的设计思考后再进行规划设计,使其设计效果和使用功能都达到了国家级示范高中的标准,推动了教育改革向更深层次发展。     

Temporal changes of soil physical quality under two residue management systems

Although crop residue management is known to affect near‐surface soil physical quality, little is known about the temporal variability of these indicators over short time intervals. This study evaluates the temporal changes of nine indicators of soil physical quality. These are organic carbon content, structural stability index, bulk density, macroporosity, air capacity, relative field capacity, plant available water capacity, Dexter's S‐index and saturated hydraulic conductivity. A second set of soil physical indicators, based on the distribution of soil pore volume, was also evaluated. The indicators were determined in three different times during the growing cycle of winter durum wheat cultivated within a long‐term field research carrying out in Southern Italy and comparing two types of crop residue management, that is, burning (B) and soil incorporation (I). Only the bulk density changed over time for both treatments, although the air capacity also changed for the incorporation of wheat residues. Residual effects of the autumnal soil tillage and soil compaction were a common source of variability, irrespective of which treatment was used. Based on the existing guidelines for evaluating the physical quality of these agricultural soils, optimal or near‐optimal values were detected in about half of the cases under consideration. This suggests that both B and I create sufficiently good conditions for crop growth during the crop cycle. The comparison between observed and optimal soil pore distribution function was always poor. The pore volume distributions showed lower densities of small pores and relatively higher densities of large pores than the proposed optimal distribution. This study also suggests that the considered optimal or references curves probably cannot be applied successfully to a wide range of agricultural soils.     

风砂土白萝卜3414肥料试验

从2010 ～2012年连续3年开展30项白萝卜3414田间肥效试验,结果表明：在试验条件下,白萝卜每667 m2最佳经济施肥量N、P2O5、K2O分别为9.50 kg、3.55 kg和15.94 kg,N：P2O5∶ K2O为1∶0.37∶1.68.     

巴音温都尔沙漠典型植物群落土壤物理性质研究

巴音温都尔沙漠是我国北方干旱气候带典型的环境敏感区和生态脆弱区,生态建设和植被恢复对巴音温都尔沙漠生态系统服务功能极为重要。本研究以巴音温都尔沙漠梭梭、唐古特白刺、球果白刺、盐爪爪、膜果麻黄群落土壤为试验对象,对不同植物群落类型土壤物理性状和持水能力进行了研究。结果表明:5种群落中土壤孔隙度、土壤毛管孔隙度与土壤非毛管孔隙度最大值均出现在盐爪爪群落,其土壤通透性最好,具备良好的通气透水能力;膜果麻黄群落土壤最为紧实,通气透水能力最差。5种群落中,盐爪爪群落土壤自然含水率最高,膜果麻黄群落最低。盐爪爪群落土壤持水量最高,麻黄群落土壤持水量最低。盐爪爪群落土壤具有良好的保水能力,膜果麻黄群落土壤保水能力处于偏低水平。     

Effect of crop residue biochar on soil acidity amelioration in strongly acidic tea garden soils

Strongly acidic soil (e.g. pH < 5.0) is detrimental to tea productivity and quality. Wheat, rice and peanut biochar produced at low temperature (max 300 °C) and differing in alkalinity content were incorporated into Xuan‐cheng (Ultisol; initial pH_{soil/water = 1/2.5} 4.12) and Ying‐tan soil (Ultisol; initial pH _{soil/water = 1/2.5} 4.75) at 10 and 20 g/kg (w/w) to quantify their liming effect and evaluate their effectiveness for acidity amelioration of tea garden soils. After a 65‐day incubation at 25 °C, biochar application significantly (P < 0.05) increased soil pH and exchangeable cations and reduced Al saturation of both tea soils. Association of H⁺ ions with biochar and decarboxylation processes was likely to be the main factor neutralizing soil acidity. Further, biochar application reduced acidity production from the N cycle. Significant (P < 0.05) increases in exchangeable cations and reductions in exchangeable acidity and Al saturation were observed as the rate of biochar increased, but there were no further effects on soil pH. The lack of change in soil pH at the higher biochar rate may be due to the displacement of exchangeable acidity and the high buffering capacity of biochar, thereby retarding a further liming effect. Hence, a significant linear correlation between reduced exchangeable acidity and alkalinity balance was found in biochar‐amended soils (P < 0.05). Low‐temperature biochar of crop residues is suggested as a potential amendment to ameliorate acidic tea garden soils.     

Short and long‐term distribution with depth of soil organic carbon and nutrients under traditional and conservation tillage in a Mediterranean environment (southwest Spain)

The impacts of tillage and cropping sequences on soil organic matter and nutrients have been frequently reported to affect the uppermost soil layers, but there is little published information concerning effects at greater depth. This article reports results on the distribution of soil organic carbon (SOC), active carbon (AC), N, Olsen‐P and extractable K within 100 cm in short (4 yr) and long (16 yr) term experiments under different tillage systems. Short (TT₄) and long (TT₁₆) traditional tillage are compared with conservation tillage, reduced (RT₁₆) and non‐tillage (NT₄). The results show more accumulation of SOC in the near‐surface under RT₁₆ and NT₄ in both experiments compared with traditional tillage. Moreover, greater C content occurs to 40 cm depth in the long‐term experiment. The results demonstrate the importance of time on C accumulation, not only in near‐surface layers but also at greater depths. Active C is an indicator of the increase in soil quality in the long‐term experiment. This trend is only apparent for the first 10 cm in the short‐term experiment. Patterns in N, Olsen‐P and extractable K are similar to that of SOC. However, only extractable K is significantly greater in soil under conservation tillage (RT₁₆ and NT₄) after short and long periods. Potassium availability is a good indicator of the changes caused by tillage. Our results indicate that studies of soils at depth could be very useful in long‐term experiments to demonstrate the effect of conservation tillage on C and nutrient distribution.     

Relative Efficiency Evaluation on Water Resource Utilization

Water resource allocation was defined as an input-output question in this paper, and a preliminary input-output index system was set up. Then GEM （group eigenvalue method）-MAUE （multi-attribute utility theory） model was applied to evaluate relative efficiency of water resource allocation plans. This model determined weights of indicators by GEM, and assessed the allocation schemes by MAUE. Compared with DEA （Data Envelopment Analysis） or ANN （Artificial Neural Networks）, the mode was more applicable in some cases where decision-makers had preference for certain indicators