在不同地区的城市环境工程中,构建系统化的污水治理体系非常关键,相关部门需要从生态环保等管理原则入手,对城镇污水处理中存在的不足和问题进行集中处理.科学有效的城市污水治理措施,需要建立在法律法规基础上,对不同规模的污水处理厂和管网系统进行集中部署.本文将着重探究生态环保视域下城市环境工程的污水治理措施.

为了探索临夏州温室大棚番茄在水肥菌一体化技术条件下的最佳追肥量和灌水量,利用膜下滴灌水肥菌一体化技术,设置番茄4个追肥量(纯养分)处理,即T1:720 kg/hm2;T2:960 kg/hm2;T3:1320 kg/hm2;T4:1800 kg/hm2,4个灌水量处理,即T5:840 m3/hm2;T6:1260 m3/hm2;T7:1750 m3/hm2;T8:2310 m3/hm2.结果表明:当地温室大棚番茄的产量最高的追肥量处理为T4(1800 kg/hm2),灌水量处理为T8(2310 m3/hm2).经过追肥量、灌水量与番茄产量的拟合函数发现,追肥量和灌水量与番茄的产量之间呈现一元二次函数关系,由函数方程计算,当地温室大棚番茄的最佳追肥量不要超过2047.5 kg/hm2,最佳灌水量不要超过2670 m3/hm2.

To study the sustainable development state of arable land resource in Linxia prefecture,the authors used the model of ecological footprint to dynamically analyze the ecological footprint of arable land in Linxia prefecture during 2002-2015.The results showed that per capita ecological footprint of arable land in Linxia prefecture increased from 0.2858 hm2 to 0.4753 hm2,which increased by 66.31％ during 2002-2015.Ecological capacity of per capita decreased from 0.2775 hm2 to 0.2431 hm2,which decreased by 12.40％ during 2002-2015.Arable land in Linxia prefecture did not have ecological surplus,ecological deficit of per capita grew from 0.0083 hm2 to 0.2322 hm2,which increased by 26.98 times.Throughout the study time scale,the ecological deficit showed a rapid growth trend.The results showed that agricultural production of arable land resources in Linxia prefecture was beyond the scope of ecological capacity,coupled with the growth of population,the relation between people and arable land became more and more tense,resulting in growing instability of arable land ecosystem,and the use of arable land resources was in an unsustainable state.Finally,the authors put forward some recommendations accordingly.

本文规定了临夏州日光温室无公害西葫芦水肥菌一体化技术栽培的产地环境、农药和化肥使用、微生物菌肥使用、水肥菌一体化系统、西葫芦无公害栽培、田间管理、病虫害防治等生产技术流程和要求,以期为临夏州农业节水与土壤肥料管理提供参考.

从范围、 规范性引用文件、 术语和定义、 产地环境、 农药和肥料使用要求、 水肥菌一体化系统要求、 生产技术、 病虫害防治、 采收及后续管理、 清洁温室等方面规范了临夏州日光温室无公害番茄水肥菌一体化栽培技术.

分析了不合理施肥对土壤物理性质、化学性质、生物性质及重金属元素积累的影响,提出了使用科学施肥技术;开发新型肥料;改革耕作制度;发展生态农业;强化环保意识,加强监测管理等防治措施.

近20年现代生物技术的发展取得了世人瞩目的成就,在各生产领域展示了广阔的发展前景.本文阐述了生物技术的发展特点,及其在社会发展中的多方面应用,生物技术对人类的生存和发展具有及其重要意义.

由于经济形势和经济环境的转变,我国"供给侧"与"需求侧"的矛盾越来越突出,本文浅谈了供给侧结构性改革的定义及其提出背景,以及当前供给侧改革包括的核心内容,最后提出了几点建议.

为了探索和政县冬小麦的最佳经济产量和最佳施肥量，根据“3414”田间试验结果建立了和政县冬小麦肥料效应回归方程。结果表明，和政县冬小麦最佳经济产量为4505.25～7246.95 kg/hm2之间，平均为5926.5 kg/hm2，氮、磷、钾最佳经济施肥量平均值依次N为159.45 kg/hm2、P2O5为99.9 kg/hm2、K2O为46.35 kg/hm2，最佳氮、磷、钾配比为N∶P2O5∶K2O=1∶0.63∶0.29，经济效益最好的处理为N3P2K2和N2P2K2。

To solve the problem of soil phosphorus accumulation and fixation in calcareous soil,extraction experiments were conducted to investigate the effect of organic acids with low molecular weight(LMW) on phosphorus activity in different fertile calcareous soils.The results showed that the organic acids could significantly stimulate the mobilization of soil phosphorus in all three soils tested.When in the same concentration,the three organic acids followed an order of oxalic acid>citric acid>malic acid in the capability of activating soil phosphorus in the low fertility and moderate fertility soil;In the high fertility soil,the three followed the order of citric acid>oxalic acid>malic acid.Low concentration of organic acids(≤2 mmol/L) could significantly restrained soil phosphorus activity in low and moderate fertility soil,especially for the malic acid.LMW organic acids could decline the pH of soil extract significantly,and the citric acid showed the strongest declining capacity. Meanwhile,for the same kind of organic acid,the extent of phosphorus activating decreased with the increasing of soil pH.

Forms of P and P sorption parameters in soils under different crop rotation systems in a 26a long-term fertilization field experiment in an arid loess plateau were determined for study of effects of crop rotation and fertilization on forms and adsorption of the phosphorus in the soil and relationships between soil phosphorus adsorption parameters and phosphorus forms.Results show that both long-term crop rotation and long-term fertilization reduced the maximum P adsorption capacity(Qm) of the soil;relative to other crop rotation and continuous cropping systems,the application of nitrogen and phosphorus fertilizer(NP) reduced Qm of the soil under the Wheat-Corn-Pea crop rotation system,and the application of NP plus organic manure(NPM) had a similar effect on Qm of the soil under the Wheat-Corn crop rotation system.The same in fertilization,the Wheat-Corn rotation and Wheat-Pea rotation systems significantly increased the contents of various forms of inorganic phosphorus,and the soils were higher in available P under long-term crop rotation than under continuous cropping,especially in Ca2-P.Correlation analysis shows that Qm and phosphorus sorption index(PSI) were significantly negatively related to total phosphorus(T-P),Olsen-P,CaCl2-P,Ca2-P,Ca8-P,Fe-P,Ca10-P and organic phosphorus(p<0.01),and to occluded phosphorus(O-P,p<0.05),too,but insignificantly to Al-P.Soil organic matter(SOM) was found to be in extremely significant negative relations to Qm,PSI and maximum buffer capacity(MBC),but in positive one related to the degree of P sorption saturation(DPSS).Path analysis and stepwise regression analysis show that among the inorganic phosphorus fractions in calcareous Heilu soil,Ca2-P contributed the most to Olsen-P.

Soil P and its sorption parameter of different fertilization treatments under 26-year long-term fertilizing field experiment on loess arid plateau were determined.Meanwhile,soil P leaching change-point was measured by lab cultivating experiment.Relations between part of soil properties and soil P adsorption parameter or P leaching change-point were studied,as well as the relationship between soil P adsorption parameters and P leaching change-point.The results showed: after 26 years of long-term fertilization,contents of Olsen-P of M75P60 and M75N120P60 respectively increased 10.7 and 9.8 times than CK treatment and content of T-P respectively increased 60.4% and 57.7% than CK treatment.Long-term application of phosphorus fertilizer and organic fertilizer reduced the maximum P adsorption capacity(Qm) of the soil,but increased the degree of P sorption saturation(DPSS) of the soil,the Qm of M75N120P60 reduced 49.92% than CK treatment,but DPSS of M75N120P60 increased 21.5 times than CK treatment.There was highly significant negative correlations between Qm and Olsen-P,T-P or CaCl2-P(P<0.01) and significant negative correlation between Qm and SOM(P<0.05).There was highly significant positive correlations between EPC0 and Olsen-P or CaCl2-P and significant positive correlations between EPC0 and T-P or SOM,while the relationship with pH value was not significant,but MBC was highly related to pH value.DPSS was highly related to Olsen-P,T-P,CaCl2-P and SOM.The leaching change-point of soil Olsen-P had very significant positive correlation with Qm,and had significant positive correlation with MBC,while the relationships between it and DPSS、Olsen-P、Total-P or Ca Cl2-P was very significant.Results also indicated the value of soil Olsen-P leaching change-point of loess soil arid land coincided with DPSS15% value,namely,the value of DPSS15% can be taken as soil Olsen-P leaching change-point of the present study area.

To explore the effective way to improve soil phosphorus availability, indoor incubation experiments were conducted. So, the effect of low molecular weight（LMW） organic acids on organic phosphorus fraction and its availability in calcareous soil was investigated. The results showed that the LMW organic acids could significantly stimulate the soil available phosphorus. For calcareous soil, the ability of oxalic acid in mobili- zing soil available phosphorus was higher than that of malic or citric acid~ citric and malic acid could signifi- cantly restrained soil available phosphorus activity in calcareous soil. The content of soil available phosphorus decreased with the lengthened of the incubation time. Moreover, with the increase of oxalic acid concentra- tion, or the decrease of citric and malic acid concentrations, the content of soil available phosphorus increased. After disposed by LMW organic acids, the contents of liable organic phosphorus（L-OP）, moderate liable organic phosphorus（ML-OP）, and moderate stable organic phosphorus（MS-OP） increased, while the content of high stable organic phosphorus（HS-OP） decreased in calcareous soil. As a conclusion, LMW organic acids can improve the soil phosphorus availability by affecting the organic phosphorus fractions.

Studies regarding plant phosphorus accumulation and utilization efficiency can provide scientific basis for reasonable application of phosphate.Dynamics of phosphorus content of winter wheat and utilization efficiency of winter wheat was conducted based on the long-term positional fertilization experiment on dry highland of the Loess Plateau.The results show that the phosphorus contents of winter wheat plants with application of phosphate fertilizer presented a V shape curve.Phosphorus contents of winter wheat were high during the early growth period,and decreased with the crop growth,and reached the minimum in the filling stage,and then rebounded in the last stage.Phosphorus of winter wheat accumulated mainly in two stages,i.e.,stage of jointing—flowering and stage of filling—mature.Sufficient supply of phosphorus in these two stages could ensure better growth of winter wheat.In terms of phosphorus utilization efficiency,yield and other indicators,phosphate application should be controlled in a reasonable range between 45～90 kg/hm2 in the scenario of nitrogen application 90 kg/hm2.

The study on soil particle composition and enrichment of available phosphorus was conducted with a long-term fertilization field experiment and laboratory analysis methods.The results showed the smaller soil particle was,the higher the proportion of soil particles was in four fertilization treatments,but the different fertilizer treatments would influence the proportion of the same particle size.The combined application of nitrogen fertilizer,organic fertilizer on the basis of a single P application(NP、PM、NPM),would help to increase the 0.25 mm proportion of particles,the NPM was the most obvious.The long-term application of organic fertilizer could improve available phosphorus in soil particles,in same time the proportion of the water-soluble phosphorus in available phosphorus of the soil particles may be increased.Available phosphorus in the soil(including Olsen-P,water-soluble phosphorus) mainly enriched in the 2 mm soil particles,the highest enrichment rate of available phosphorus was in 0.25 mm soil particles.The combined application of nitrogen and phosphorus fertilizer(NP) or nitrogen,phosphorus and organic fertilizer(NPM) could significantly improve enrichment rate of available phosphorus in 0.25 mm soil particles,but the application of phosphorus and organic fertilizer(PM) could increase enrichment rate of available phosphorus in 0.25~2 mm soil particles.