浅议修缮购置专项预算编制与会计核算问题

文章阐述了修购专项实施的重要意义;指出了修购专项在预算编制与会计核算中存在的问题;并提出了规范化建议:一是提高预算编制水平;二是规范会计核算,确保会计信息的准确完整;三是完善资产入账手续,确保资产不重不漏。     

榆中县农用地土壤及其蔬菜中重金属含量的分析与评价

为研究榆中县农田土壤和所产蔬菜中重金属污染情况,选取具代表性的农田采集收获期耕层土壤和蔬菜,分析和评价了土壤和蔬菜中Cd、Cr、Hg、Pb、Cu、Zn的含量及污染程度.结果表明:1)土壤样品中Cd、Cu、Zn的含量均超过兰州市土壤背景值,Cr有33.3％的样品超过兰州市土壤背景值,而Pb样品均未超过兰州市土壤背景值的含量,Hg的含量未检出;与国家土壤环境质量标准(GB15618-1995)中II级标准相比较,只有Cd含量超过国家标准限值,而Cr、Cu、Pb、Zn等均未超过国家标准限值.土壤中重金属相关分析表明,Cd、Cr、Zn不具有相同来源,而Pb、Cu具有相同来源的可能性大.2)蔬菜样品中重金属Cd、Cr、Cu、Pb、Zn的含量均超过国家标准限值,其中,Cr的超标倍数最高为16.56,说明,蔬菜样品中受Cr的污染最严重,而Cd、Pb、Zn和Cu的污染也属重污染程度.采用单因子污染指数法和综合污染指数法以国家土壤环境质量(GB15618-1995)II级标准为评价标准计算污染指数,结果表明,土壤重金属的单因子污染指数只有Cd达到重污染水平,其他重金属元素均属清洁水平,而综合污染指数为3.423,已达重污染程度.以GB184061-2001中的重金属限量值为评价标准,蔬菜重金属的单因子污染指数Cd、Cr、Pb、Zn达重污染水平,只有Cu为轻度污染,而综合污染指数为12.43,已经达非常严重的污染程度.     

木薯器官及其混合物水浸提液对橡胶树棒孢霉落叶病病菌的化感作用

采用生长速率法探讨不同浓度木薯器官及其混合物水浸提液于不同处理天数对橡胶树棒孢霉落叶病病菌的化感作用。结果表明:(1)根、叶水浸提液表现为化感抑制效果,浓度越大,效果越明显。(2)茎水浸提液在浓度为10~100 mg/mL时无明显化感效果;浓度达1 000 mg/mL时,处理后3~7 d时表现为显著的化感促进效果。(3)根、茎、叶比例为4:2:1的混合物水浸提液在10~100 mg/mL浓度时无明显化感效果,当浓度达1 000 mg/mL时,在处理后4~6 d表现为化感抑制效果。(4)茎、叶比例为2:1的混合物水浸提液在10 mg/mL浓度时化感效果不明显;当浓度达到100 mg/mL时,处理后2 d表现为显著的化感抑制效果,处理后3~6 d化感效果不明显;浓度达到1 000 mg/mL时,处理后2~3 d无明显的化感效果,处理后4~6 d则呈现显著的化感促进效果。建议间作木薯的胶园收获木薯后,应及早将茎干移出胶园,以减少橡胶树棒孢霉落叶病的发生。      

我国北部及中东部地区玉米根际土壤中寄生线虫种类调查研究

对我国北部及中东部9省(直辖市)的57市(县)采集玉米根际土壤样品,从92份土样中共分离到17属植物寄生线虫,即垫刃属(Tylenchus)、丝尾垫刃属(Filenchus)、杆垫刃属(Rhabdotylenchus)、平滑垫刃属(Psilenchus)、叉针属(Boleodorus)、巴兹尔属(Basiria)、矮化属(Tylenchorhynchus)、短体属(Pratylenchus)、小环属(Criconemella)、茎属(Ditylenchus)、纽带属(Hoplolaimus)、盾属(Scutellonema)、盘旋属(Rotylenchus)、螺旋属(Helicotylenchus)、拟盘旋属(Pararotylenchus)、真滑刃属(Aphelenchus)、滑刃属(Aphelenchoides)。其中,矮化属线虫分布较广,占样本总数的58.70%;螺旋属线虫的相对丰度最大,占线虫总数的47.53%,这两属线虫为玉米根际土壤中的优势属。对不同地区线虫种群进行分析得出,螺旋属线虫为山东、安徽、江苏及河南省的优势属,矮化属线虫为黑龙江、吉林、辽宁、北京和河北省(市)的优势属,垫刃属线虫是吉林省的优势属,短体属线虫为辽宁和河南两省的优势属。     

Principal Response Curves analysis of polyphenol variation in resistant and susceptible cotton after infection by a root-knot nematode (RKN)

The root-knot nematode (RKN), Meloidogyne incognita, attacks cotton root system. This study aimed to compare the induction of phenolic compounds over time in two cotton genotypes, resistant (TX-25) and susceptible (FM966), by RKN. Chemical profiles of cotton roots were obtained by HPLC, NMR, and colorimetric methods at four different time intervals. The Principal Response Curves analysis, a time-dependent, multivariate method, showed consistent variability over time in the profile of phenolic compounds between treatments for both genotypes. The variables that most contributed to the divergence between damaged and undamaged cotton roots were dimethoxylated and non-methoxylated gossypols, total flavonoids, and total phenols.     

机插秧稻田二次封闭控草应用技术

稻田草害是机插秧生产中最严重的问题。传统水稻田一封二杀三补控草策略策略已经不能适应机插秧的除草要求。本文综合小区试验和大区示范,针对不同栽培条件下的土壤和杂草情况,提出二封一补的除草对策。3年试验示范结果表明,土地平整后插秧前使用57%苄·丙·异丙隆可湿性粉剂1 500~1 800 g/hm~2进行第1次封闭处理,插秧后10 d用50%苄·丁·异丙隆可湿性粉剂1 200~1 500 g/hm~2进行第2次封闭,既能有效控制早期杂草为害,保证秧苗安全,又能延长对杂草持续控制作用,提高水稻产量。在2次封闭基础上,针对不平整地块和烤田后抗性杂草发生情况,提出相对应的补治措施。     

The influences of reseeding date and mowing prior to reseeding on establishment of alfalfa in Leymus chinensis meadows北大核心CSCD

This research studied the effects of sowing date and cutting prior to sowing on establishment of the leguminous forage,alfalfa（Medicago sativa）,in a lightly degraded Leymus chinensis meadow and investigated the sowing date×cutting interaction. The factorial experiment comprised four sowing dates（May 1,June 1,July 1,August 1）and cutting treatment（cut or uncut）prior to sowing,and evaluated the establishment performance of alfalfa and the ecological mechanisms related to establishment. It was found that soil moisture during emergence of alfalfa was the greatest when sowing occurred on July 1,and clipping prior to sowing significantly decreased the plant height of L. chinensis during emergence and seedling growth of alfalfa. There was a significant sowing date×cutting interaction effect on alfalfa establishment. Clipping prior to sowing significantly increased the emergence percentage of alfalfa through reducing the plant height of L. chinensis and associated above-and below-ground competition,and the seasonal soil moisture change resulted in a 20% higher（P<0. 05）alfalfa emergence rate when sowing occurred on July 1. With cutting,the number of surviving alfalfa seedlings and seedling survival rate were greatest（83 plants· m−2 and 53%,respectively）when sowing occurred on July 1. For later sowing,owing to the shortened growing time,the development and overwintering survival rates of alfalfa seedlings were significantly reduced. Cutting prior to sowing significantly increased the overwintering rate of alfalfa seedlings through improving their development. In the cutting treatment,the number of overwintered alfalfa seedlings（22 plants·m−2）when sowing was on July 1 was significantly higher than for other reseeding dates. In the second year,a botanical composition measurement showed that clipping prior to reseeding significantly increased the alfalfa biomass within the meadow,and the alfalfa biomass was significantly greater than in other treatments when sowing occurred on July 1 after cutting. Cutting prior to sowing also significantly increased the crude protein content of forage. Based on these research results,normal production practice should include cutting when alfalfa is sown into L. chinensis meadow. Combined with cutting,a sowing date around July 1 is the most favorable for the establishment of alfalfa. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.     

放牧管理模式对高寒草甸草原土壤养分特征的影响

为探讨不同放牧管理模式下高寒草甸草原土壤养分特征的变化,对青藏高原东缘禁牧(NG)、全生长季休牧(RG)、传统夏季休牧(TG)和连续放牧(CG)4种放牧管理模式下高寒草甸草原土壤有机质、全氮、全磷、全钾、速效氮、速效磷和速效钾含量进行测定和分析。结果表明:(1)NG显著增加了0~30cm土层有机质含量,RG和TG显著增加了0~20cm土层有机质含量;(2)NG,RG和TG显著提高了高寒草甸草原0~30cm土层全氮含量和20~30cm土层速效氮含量,而降低了0~10cm土层的速效氮含量;(3)NG,RG和TG显著提高了高寒草甸草原0~30cm土层全磷和速效磷含量;(4)不同模式放牧对高寒草甸草原土壤全钾含量无显著影响,但总体上,NG,RG和TG高于CG;NG,RG和TG降低了0~10cm土层速效钾含量,而显著增加了10~30cm土层速效钾含量。连续放牧使土壤养分流失严重,从而导致土壤肥力降低,而禁牧和季节性休牧能有效增加青藏高原东缘高寒草甸草原土壤的养分含量,是该区和类似区域草地放牧管理的理想选择。     

免耕对土壤微生物量碳影响的Meta分析

为综合分析免耕(NT)对土壤微生物碳含量的影响程度,以常规耕作(CT)为对照,收集国内外关于免耕对土壤微生物碳研究已公开发表的41篇文献的田间试验数据162组,采用Meta数据整合分析方法,定量分析中国不同区域、气候类型和试验年限下,免耕对于中国农田土壤微生物碳含量的影响。结果表明,与常规耕作相比,免耕能显著提高土壤微生物碳的含量,免耕-常规耕作(NT-CT)的加权均数差值(WMD)为49.29 mg·kg^-1;免耕对土壤中微生物碳含量的影响存在区域差异性,西南地区WMD最大,湿润区(年降雨量>800 mm)免耕对土壤微生物碳含量的正效应最显著;年均温度10~15℃和年均温度>15℃时,免耕土壤中微生物碳含量显著高于常规耕作,且随着温度的升高而增加;免耕年限能够显著影响土壤微生物碳含量,以长期免耕(免耕年限≥8 a)效果最佳。综上,免耕对土壤微生物碳的增加效应存在区域特征,以西南地区最高,随着区域水热条件、免耕年限的不同有所差异,免耕措施的采用应该根据区域特点因地制宜。本研究结果为免耕的区域性合理利用提供了参考依据。     

池塘系统在农村面源污染防治中的应用

 农村生活污水是农村面源污染的重要来源。通过为期1年的农村污水水质监测,研究松花坝水源区建立池塘系统对农村污水的净化效果。结果表明:1)池塘系统对铵氮、总氮、总磷的输出具有较好的控制效果,最高去除速率分别为3.78、4.20、1.06g/(m2.d),最大去除率分别为88.35%、79.28%、86.49%;2)由于硝化和反硝化作用同时存在,硝态氮的含量变化不能准确地反映池塘对硝态氮的去除效果;3)池塘系统对污染物的去除效果与污染物的输入速率呈负相关关系。研究结果可为松华坝水源区农村面源污染治理提供一定的理论依据。