大气CO2浓度的升高、施氮及土壤水分对春小麦干物质积累和氮吸收的影响

Spring wheat (Thiticum aestivum L.cv.Dingxi No.8654) was treated with two concentrations of atmospheric CO2 (350 and 700 μmol mol^-1),two levels of soil moisture (well-watered and drought) and five rates of nitrogen fertilizer(0,50,100,150,and 200 mg kg^-1 soil) to study the atmospheric CO2 concentration effect on dry matter accumulation and N uptake of spring wheat.The effects of CO2 enrichment of the shoot and total mass depended largely on soil nitrogen level,and the shoot and total mass increased significantly in the moderate to high N treatments but did not increase significantly in the low N treatment.Enriched CO2 concentration did not increase more shoot and total mass in the drought treatment than in the well-watered treatment.Thus,elevated CO2 did not ameliorate the depressive effects of drought and nitrogen stress.In addition,root mass decreased slightly and root/shoot ratio decreased significantly due to CO2 enrichment in no N treatment under well-watered condition.Enriched CO2 decreased shoot N content and shoot and total N uptake;but it reduced root N content and uptake slightly.Shoot critical N concentration was lower for spring wheat grown at 700 μmol mol^-1 CO2 than at 350μmol mol^-1 CO2 in both well-watered and drought treatments. The critical N concentrations were 16 and 19 g kg^-1 for the well-watered treatment and drought treatment at elevated CO2 and 21 and 26 g kg^-1 at ambient CO2,respectively. The reductions in the movement of nutrients to the plant roots through mass flow due to the enhancement in WUE (water use efficiency) and the increase in N use efficiency at elevated CO2 could elucidate the reduction of shoot and root N concentrations.     

重庆酸性紫色土马铃薯的高产优质与养分平衡

Over a period of two years,field experiments were conducted on four silty loam soils grown with foliar vegetable crops inculding Chinese cabbage(Brassica pekingensis Rupr.,cv.Lu-Bai 3),autumn greens (B.chinensis L.,cv.Piao-Geng-Bai),winter greens(B.var.rosularis Tsen et Lee,cv,You-Dong-Er),and summer greens(B.chinensis L.,cv.Zao-Shu5),respectively,Each eperimpent included one CK treatment without K,N and Pfertilizers applied,and four treatments with from low to high doses,0-300 kg hm^-2 for Chinese cabbage,0-150 kg hm^-2 for autumm and winter greens and 0-180 kg hm^-2 for summer greens,of K fertilizers in the form of sulfate of potash(SOP)applied together with N and P fertlizers,One treatment of K fertilizer in the form of muriate of potash(MOP) applied at high levels(150 or 180 g hm^-2)together with N and P fertilizers was included in the experiments of autumn,winter and summer greens ,respectively,in order to compare the effcts of SOP and MOP ,The market yields of the tested crops incresaed significantly with the increasing rate of K application.The crops supplied with K fertilizers yielded more stably as the CV% of their yields decreased with the rate of K application.K fertilization increased not only K contents but also the amounts of N ,P and K absorbed in shoots of autumn,winter and summer greens,which were atatistically significantly correalted to their yields.In can aslo be found that potassium improved the quality of the foliar vegetable crops as their dry mater contents were generally increased and Vc contents obviously increased and nitrate contents markedly decreased ,As compared to MOP,SOP was more effective on the yields and quality of autumn,winter and summer greens at the high levels of fertilization.     

不同种类中国杉对土壤养分状况的影响

The effects of different types of Chinese fir stand,including those with varous composition (pure and mixed),in various cropping systems (first and continuous cropping system)and at different ages,on the nutrient status of soils the hilly regions of southern Anhui Province were studied by means of ecological sequential comparison on the basis of similar climate and soil type.The work was carried out in the Xiaoxi Forest Farm of Jingxian County and the Caijiaqiao Forest Farm of Jingde Coundy,where the soil is parayellow soil derived from phyllite and sandstone,The results revealed that with the increase of age,Chinese fir pure stand could accumulate organic matter and nitrogen in the soil but it resulted in decreasing of soil pH and base ions(especially Ca^2 ) compared to its mixed stand with broad-leaf trees such as Chinese sassafras,In order to improve the soil fertility,It would be better to mix Chinese fir with broad-leaf trees when afforestation In the management of Chinese fir pure stand,base compounds and phosphates should be added to the soil for mintaining soil fertility and raising and raising forest productivity.     

番茄不同生育期遮荫对其干物质分布、产量及叶片养分含量的影响

Pot-grown tomato plants (Lycopersicon esculentum Mill. cv. Maofen) was used to study the effects of three shading levels (0, 75% and 40%) for 8 days on dry matter partitioning, contents of nitrogen (N),phosphorus (P) and potassium (K) in leaves and yield at three growth stages (early flowering (EF), peak flowering (PF) and later flowering (LF)). Shading reduced the dry weight of root and stem tissues at the EF and PF stages, but the 40% shading increased root dry weight and stem dry weight by 43.2% and 21.6%,respectively, at the LF stage. The influence of shading on the dry weight of leaves was very small at most growth stages. Shading had no effects on total leaf N, P and K contents at the EF and PF stages, showing that N, P and K absorption were regulated by the carbon assimilation at these two stages. The leaf N, Pand K contents of 40% shaded plants at the LF stage were significantly increased. There were no obvious differences in leaf N and K contents between 75% and 40% shading treatments, but significant difference in leaf P contents was found between them at the LF stage. Shading significantly enhanced the friit yield of 40% shaded tomato plants at the LF stage, but failed to affect the fruit yield of shaded plants at the EF stage. These showed that tomato could grow well and a better yield could be obtained if some moderate shading (i.e., 40% shading) was applied at the LF stage at s, mmer midday.     

规模化猪场固体粪便收集系数与成分测定

为初步探讨规模化猪场不同饲养阶段固体粪便的实际收集量,该文选择北京一典型规模化猪场,定期对采用干清粪工艺的保育猪、育肥猪、妊娠母猪和分娩母猪的固体粪便日收集系数进行测量和相关成分测定,为估算规模化猪场固体粪便收集量和相关污染负荷提供依据。结果表明:妊娠后期母猪,妊娠前期母猪,分娩母猪、育肥猪和保育猪的固体粪便平均收集系数分别为(2．19±1．10),(1．22±0．3),(1．27±0．32),(0．75±0．26)和(0．47±0．14)kg·d~(-1)·头~(-1);各饲养阶段的新鲜固体粪便的含水率基本一致,平均含水率为66％;保育猪和育肥猪的粪便挥发性固体平均含量(干基)为81．8％,分娩母猪与妊娠前期和妊娠后期母猪固体粪便挥发性固体平均含量为(干基)74．4％;保育猪与育肥猪的固体粪便有机物和大部分重金属含量比妊娠母猪和分娩母猪高。     

不同解磷菌群对油菜土壤养分与酶活性的影响

利用盆栽油菜的二因素完全随机区组设计,研究了北方石灰性土壤上施用不同解磷菌群对土壤速效养分及土壤磷酸酶、脲酶活性的影响。结果表明:不同解磷菌群施入不同P素水平土壤中,油菜整个生育期内都能不同程度地提高土壤速效养分和土壤酶活性;土壤磷酸酶活性则随P素水平增高而降低,即低P水平下磷酸酶活性较强;施用菌肥土壤磷酸酶活性高于不施用菌肥处理,施与不施菌肥处理间脲酶活性在苗期及低P水平下差异显著。     

山西省主要农田施肥状况及典型县域农田养分平衡研究

根据山西省农业统计资料,结合实地调查和土壤测定数据,采用典型农户问卷调查的方式,研究了全省和3个典型县域农田施肥状况、养分平衡和土壤养分变化趋势。农户施肥状况调查结果表明,2000年山西省平均N肥用量为181.8Nkg/hm2,P肥用量为93.7P2O5kg/hm2,K肥用量为41.9K2Okg/hm2,N∶P∶K为1∶0.52∶0.23。从化肥的投向来看,水地的施用量明显高于旱地,蔬菜和果树的施用量高于粮食作物和其它经济作物。从3个典型县域农田养分平衡来看,1980年后随着N、P肥施用量的增加,农田N素和P素出现大量盈余,K素则处于亏缺状态。通过对第二次全国土壤普查和2000年土壤测定结果分析,了解了山西省近20年来土壤有效磷和速效钾的变化趋势,以及典型县域农田养分平衡状况对土壤养分变化的影响及特点。     

下辽河平原不同水肥条件对玉米养分吸收与分配的影响

利用持续16年的长期田间试验与气象观测资料，研究了下辽河平原不同施肥与降水条件对玉米体内养分浓度、养分在籽实与秸秆中的分配比以及每形成单位籽实产量所收获养分量等的影响。结果表明，玉米体内养分浓度及养分在籽实与秸秆中的分配比例明显受施肥、降水及作物生长状况的影响。在平水年条件下，养分在籽实内累积的比例最高，其中N、P、K分别较偏旱或偏涝年景平均相对提高26.2%、33.3%和21.3%。同时，作物生长状况愈好，形成单位籽实产量所需养分量有减少的趋势，这些都说明良好的水肥条件有利作物生长，也有利于提高作物体内养分的转化利用效率。     

The Effect of Chloride on Yield and Nutrient Interaction in Greenhouse Tomato (Lycopersicon Esculentum Mill.) Grown in Rockwool

The effect of increasing chloride content in nutrient solution on nutrient composition in root environment, interaction of nutrients in leaves and yield of greenhouse tomato cv. ‘Grace F₁’ grown in rockwool were searched. In Experiment I (2004–2005) the levels of 15, 30, 60, and 90 mg Cl·L^?1 but in Experiment II (2006) 30, 60, 90 and 120 mg Cl·L^?1 of nutrient solution were tested. The sources of chloride were water (9.6–10.7 mg Cl·L^?1) and calcium chloride (CaCl₂·2H₂O) but the rest of nutrients and sodium in all treatments were on the same levels. It was found that increasing content of chloride from 15 to 60 mg Cl·L^?1 enhanced the total and marketable fruit yield. Within the range of 60 to 90 mg Cl·L^?1 the yield was on the optimum level but the content of 120 mg Cl·L^?1 declined it. Increasing chloride content in the nutrient solutions was reflected in rising of chlorine content in leaves. The concentration of chloride above 60 mg C·L^?1 reduced the content of nitrogen but above 90 mg C·L^?1 declined the content of calcium, sulfur and zinc in leaves. The antagonism between Cl:N, Cl:Ca: Cl:S and Cl:Zn was appeared. More variable interaction were between Cl:K and Cl:B. At the low levels of chloride, from 15 to 60 mg Cl·L^?1, potassium and boron content were decreased but at the higher ones, from 90 to 120 mg·L^?1, these nutrients had increasing course. It was not found out the effect of chloride contents on macro and microelement contents in nutrient solution emitted from drippers however their content upraising in root medium (rockwool). The highest increase was found out for Na 95.1 and 64.9 % (Exp. I and II - respectively), next for Ca (76.0, 70.1 %), Cu (62.5 and 71.0 %), Cl (43.6, 24.4), B (33.3, 21.0 %), N-NO₃ (30.4, 49.6 %), Zn (29.5, 32.8 %), S-SO₄ (25.9, 25.5 %), K (24.5, 24.1 %), Fe (19.8, 19.2 %), Mn (17.5, 21.3 %) and Mg (14.9, 11.7). Advantageous effect of chloride on tomato yield justified the need to introduce for the practice adequate chlorine nutrition, and recommend to maintain 60 to 90 mg Cl·L^?1 in nutrient solution. The best yield appeared when content of chlorine in leaves (8th or 9th leaf from the top) was in the range 0.48-0.60 % of Cl in d. m.     

稻草和尿素配施时水稻对肥料氮和土壤氮的吸收利用

利用＾１５Ｎ同位素示踪技术,研究了稻草和尿素配施时水稻对肥料和土壤氮的吸收。结果表明,稻草单施导致土壤速效氮的生物固定,氮素供应不足是影响水稻分蘖成穗的限制因子,稻草配合尿素施用,明显改善肥料氮和土壤氮的供应,既有利于当季水稻增产,也有利于培养土壤肥力,还有利于后茬物作产量的提高 。