首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
桂林毛村岩溶区与非岩溶区果园土壤养分性质比较研究   总被引:1,自引:0,他引:1  
研究了处于同一气候条件下岩溶区与非岩溶区果园土壤溶解有机碳的空间变化及其与土壤养分性质的关系。结果表明:岩溶区土壤pH值与土壤溶解有机碳(DOC)呈极显著负相关关系(r=-0.465,P<0.01),DOC与土壤有机碳、全氮、速效氮呈极显著正相关关系(r分别为0.347、0.574、0.444,P<0.01);非岩溶区DOC与土壤有机碳、土壤全氮含量呈正相关关系(r分别为0.187、0.191)。土壤溶解有机碳、土壤溶解有机氮(DON)与土壤微生物量碳(MBC)、土壤微生物量氮(MBN)的关系依土壤环境条件差异而不同。非岩溶区土壤的C/N较适宜土壤微生物的生长、繁殖。岩溶区与非岩溶区时空变化,导致土壤养分性质变化。  相似文献   

2.
乌苏里江上游黑斑狗鱼种群的生长特性   总被引:5,自引:0,他引:5  
于2003年秋季对乌苏里江上游黑斑狗鱼Esoz reichertl的种群结构和生长特性进行了调查研究,共采集样本840尾。结果表明:该水域的黑斑狗鱼主要由6^+龄以下个体组成,其中以3^+龄以下个体为主。体长与体重之间的关系为形:0.0051L^3.1023(r=0.9762);生长方程为L1=120.17[1-e^0.1215(t+0.5983)],Wt=15139.22[1-e^-0.1215(t+0.5983)]^3.1023;生长拐点年龄t=8.7龄,拐点体重形=4531.7g,说明黑斑狗鱼在8^#龄前均能维持较快增长。鉴于目前的捕捞状况,应对4^#~8^#龄之间的个体适当加以保护。  相似文献   

3.
【目的】以河北省廊坊市小麦-玉米轮作区沙质潮土为研究对象,通过2015—2018年田间连续定位试验,研究两种土壤改良剂对土壤活性有机碳组分含量和土壤碳库管理指数的影响,以期为沙质潮土有机碳库培育,改善土壤质量提供理论依据。【方法】试验采用单因素随机区组设计,设4个处理:(1)单施化肥(CK);(2)CK+有机改良剂15 t·hm-2(T1);(3)CK+无机改良剂2.25 t·hm-2(T2);(4)CK+有机改良剂15 t·hm-2+无机改良剂2.25 t·hm-2(T3)。收获季测定土壤有机碳、全氮、pH、速效磷、速效钾,并运用修正的内梅罗指数法计算土壤综合肥力指数(IFI)。再分析活性有机碳各组分含量,并计算碳库管理指数(CPMI)。最后通过CPMI和IFI指示指标评价连续施用土壤改良剂对沙质潮土改良的应用效果。【结果】较CK处理,施用有机改良剂处理土壤总有机碳(TOC)和土壤综合肥力指数(IFI)均显著提高,尤其是有机无机改良剂配施时效果最显著;施用有机改良剂处理各活性碳组分含量均呈升高趋势,并且活性有机碳各组分含量呈现为:易氧化有机碳(LOC)>可溶性有机碳(DOC)>微生物量碳(MBC);施用有机改良剂各处理土壤活性碳库组分有效率均呈下降趋势,T1、T3处理土壤易氧化有机碳有效率(LOC/TOC)较CK分别显著降低了12.57%和12.02%,微生物量碳有效率(MBC/TOC)较CK分别显著降低了12.84%和12.30%,单施无机改良剂处理较CK无显著影响,说明施用有机改良剂增加活性有机碳各组分含量的同时,向土壤中输入了更多的稳定态碳,进而导致有效率的降低;施用有机改良剂各处理土壤碳库指数显著升高、碳库活度显著降低,说明施用有机土壤改良剂能够促进土壤碳库的积累;施用有机改良剂各处理土壤碳库管理指数均呈升高趋势。主成分分析结果表明,施用有机改良剂能够影响土壤中活性碳各组分含量及其有效率。【结论】连续施用有机改良剂能够显著提高沙质潮土肥力,增加土壤碳库管理指数,累积碳库库容,改善土壤质量。  相似文献   

4.
旱作水稻品质性状分析   总被引:1,自引:0,他引:1  
以19份粳稻和22份籼稻为材料,研究全程旱作对水稻品质的影响.结果表明:(1) 旱作粳稻直链淀粉含量与胶稠度呈显著性负相关,旱作籼稻直链淀粉含量与其它品质性状间相关系数没有达到显著水平.(2)综合多元回归分析和主成分分析,旱作粳稻外观品质(垩白率X4、透明度X6和垩白度X5)、蒸煮品质(碱消值X7、胶稠度X8)和营养品质(粗蛋白X10)与稻米理化品质关系密切,回归方程为Y=1.485X4-0.228X5 0.710X6 35.234X7 2.646X8 0.233X10-89.552(R2=0.934**);旱作籼稻碱消值(X7)、整精米率(X3)和粗蛋白(X10)与稻米理化品质关系密切,回归方程为Y=0.966X3 59.683X7 0.149X10-37.972(R2=0.503*).初步建立旱作水稻品质评判方式.  相似文献   

5.
Ear morphological traits such as volume and shape are important features of maize and the quantitative associations among them can help understand kernel yield determination. 150 mature ears each of 4 maize cultivars were collected from field experiments, and ear length(L), diameter(D), area(S) and volume(V) were recorded for individual ears, kernel weight per ear also recorded for a portion of the examined ears. Following principles of dimensional analysis, 8 theoretical equations of 3 sets,which relate ear higher dimensions to its length and diameter, were developed and parameterized and validated with the field observations. The 3 optimized equations showed that the shape of ears in maize can be featured with 3 dimensionless form factors, namely diameter-to-length ratio(c=D/L), areal form factor(b=S/L/D), and volumetric form factor(a=V/L/D/D). Statistically,all of them were significantly different among cultivars, and a's values varied from 0.582 to 0.612, and b's 0.839-0.868, and c's 0.242-0.308. Volumetric form factor and areal form factor could estimate precisely ear volume and area respectively, but diameter-to-length ratio was not suitable to estimate ear diameter by its length. Ear volume explained almost all variation of ear kernel weight and product L*D*D did the same substantially. Dimensional analysis proved to be promising in understanding relationship among morphological traits of ears in maize. Its application in crop researches should improve our knowledge of the physical properties of crop plants.  相似文献   

6.
缓/控释复合肥料不同形态氮素释放特性研究   总被引:25,自引:2,他引:25  
【目的】探讨缓/控释复合肥料不同形态氮素养分(NH4+-N、NO3--N、Urea-N、DON和Total N)在不同介质中释放的动力学特性及生物效应。【方法】采用水中溶出法、土壤恒温培养法和盆栽生物试验。【结果】不同培养介质中,缓/控释复合肥5种形态氮素养分的累积释放量随时间的动态变化可用一级动力学方程Nt=N0(1-e-kt)、Elvoich方程qt=a+blnt、抛物线扩散方程qt=a+bt0.5表征,并以一级动力学方程拟合效果最好(r=0.9569**~0.9999**),E1ovich方程次之(r=0.7705**~0.9933**)。缓释复合肥料不同形态氮素最大释放量(N0值)与其氮素累积释放量的变化规律一致,在水中以Total N>DON>Urea-N>NH4+-N>NO3--N,在土壤中则以Total N>NH4+-N>DON>Urea-N>NO3--N。以水为介质时,缓释复合肥料不同形态氮素释放速率常数(k值和b值)的变化序列均以Total N>DON>NH4+-N>NO3--N;以土壤为介质时,k值大小为Urea-N>DON>NH4+-N>Total N>NO3--N,b值则为Total N>NH4+-N>DON>NO3--N>Urea-N。与普通复合肥料相比,缓/控释复合肥的氮素利用效率(NUE)、氮素农学效率(NAE)及氮素生理效率(NPE)分别提高了11.4%、8.32 kg·kg-1和5.17 kg·kg-1。相关分析发现,5种形态氮素养分占总氮量的比值(Nx/NT)与水稻不同生育期吸收氮素养分之间呈显著或极显著正相关。【结论】定量描述氮素养分释放的动力学方程中以一级动力学方程评价更具有实效性。与普通复合肥料以单一尿素态氮养分为主相比较,缓/控释复合肥料的不同形态氮养分更有利于水稻对氮素的吸收利用。  相似文献   

7.
The solubility of stibnite ( Sb(2)S(3)) was measured at 25 degrees C and 1 atmosphere in solutions ranging from 0.45 to 7.16 percent Na(2)S by weight. Sb(2)S(3): Na(2)S mole ratios of saturated solutions range from 0.238 to 0.403. Stibnite solubility increases at an increasing rate with rising Na(2)S concentration. The reaction that best fits the experimental data is 2Sb(2)S(3) + HS- + OH-= Sb(4)S(7)(2-) + H(2)O, for which an equilibrium constant was estimated to be about 5.0.  相似文献   

8.
为研究露地条件下百合从营养生长到生殖生长过程中株高、茎上叶、花茎及花苞的生长动态过程,以百合品种‘Conca D,or’为材料,在对不同器官形态发育测量的基础上,运用Richards方程对株高、叶片、花茎、花苞等器官的实测数据进行曲线拟合,构建生长发育模型。结果表明:株高的生长量方程为Y=48.151/(1+64.478e-0.235x)1/0.235;叶片的生长量方程为:Y=3.429/(1+0.006e-0.105x)1/0.001;花茎的生长量方程为:Y=7.387/(1+2 245.212e-0.223x)1/0.963 8;花苞的生长量方程为:Y=15.313/(1+841.027e-0.136x)1/1.687,4个生长方程的决定系数R2分别为0.999、0.985、0.994和0.989,其生长量曲线的实测值与预测值高度拟合,满足“慢-快-慢”的生长规律。4个生长方程很好的揭示了百合从营养生长到生殖生长过程中各器官生长的发育规律,能够预测花苞开裂后花被片生长的情况。  相似文献   

9.
寄主日龄对啊氏啮小蜂寄生后代的影响   总被引:1,自引:4,他引:1  
啊氏啮小蜂(Tetrastichus hagenowii)是美洲大蠊卵的寄生蜂,越新鲜的美洲大蠊卵荚被寄生率越高,不同日龄卵荚寄生率(y)与卵荚日龄(x)的关系符合方程y=-0.6 943x+34.158(R2=0.9205).寄生不同日龄卵荚的啊氏啮小蜂的发育历期(y)随着美洲大蠊卵荚日龄(x)的增加而缩短,符合方程y=-0.4411x+43.404(R2=0.9467).寄生蜂的雌雄性比(y)也随着寄主日龄(x)的增大而降低,符合方程式y=-1.4349x+89.435(R2=0.9331).  相似文献   

10.
为揭示同一生活型草本植物生长期内C、N、P生态化学计量学特征,在豫西南外方山设置羊胡子草(Carex rigescens)、芒草(Miscanthus sinensis)、野菊花(Dendranthema indicum)样地,测定生长期内叶片C、N、P含量及其生态化学计量比。结果表明:同一生活型种间植物叶片化学计量学特征具有多变性,胡子草、芒草、野菊花等3种植物生长期内叶片C含量平均为447.6 g/kg、448.1 g/kg和459.9 g/kg,N含量为26.8 g/kg、23.5 g/kg和25.6 g/kg,P含量为1.9 g/kg、1.5 g/kg和2.0 g/kg;3种植物综合变异系数排序为P含量(45.0%)C/P值(33.2%)N/P值(30.1%)C/N值(26.0%)N含量(25.3%)C含量(2.0%),C含量最稳定,N含量次之,P含量较不稳定;C含量与N、P含量负相关性均不显著(P0.05),P含量与N含量正相关性极显著(r=0.736,P0.01),N含量与C/N值负相关性极显著(r=-0.700,P0.01),P含量与C/P值负相关性极显著(r=-0.891,P0.01),C/N值与C/P值正相关性显著(r=0.283,P0.05);植物种类对叶片C含量影响显著(P0.05),N含量、P含量、C/N值与C/P值主要受生长期采样时间的影响(P0.05),物种种类与采样时间对N/P值影响不显著(P0.05)。研究区域植物叶片生态化学计量特征时,应考虑植物种类与生长期的影响。  相似文献   

11.
以木兰林管局北沟林场内的典型的针阔混交-人工林的山杨为对象,经过5 a对标准地山杨等树种进行了调查研究,利用分层切割法对山杨生物量等进行测定。结果表明:1)混交林中山杨单株总生物量的变化范围是4.10~344.16 kg,其生物量各器官分配百分比为:干均值为63.03%(53.21%~69.14%),枝均值为11.40%(5.26%~18.12%),根均值为20.12%(16.69%~22.67%),叶均值为5.44%(3.42%~8.46%)。2)山杨树高、胸径与各器官生物量有较高的相关性,建立的山杨生物量最优模型为:W=干111.985D1.702; W=1702枝119.21(D2H)0.578; W=20578根1/(0.000 012 1+0.001 91&#215;0.77D); W=叶1/(0.000 033 3+0.003 69&#215;0.815D); W=全1 /( 0.000 002 5+0.000 003 7&#215;0.771D )。3)山杨生物量的最优模型推算林分中山杨的总生物量为33 632.98 kg·hm-2,碳储量为13 808.77 kg·hm-2,各器官分别占总碳储量的60.06%(树干)、15.40%(树枝)、5.31%(树叶)、19.24%(树根)。林分碳储量分配情况为干>根>枝>叶。  相似文献   

12.
Single crystals of the layered organic-inorganic perovskites, [NH(2)C(I=NH(2)](2)(CH(3)NH(3))m SnmI3m+2, were prepared by an aqueous solution growth technique. In contrast to the recently discovered family, (C(4)H(9)NH(3))(2)(CH(3)NH(3))n-1SnnI3n+1, which consists of (100)-terminated perovskite layers, structure determination reveals an unusual structural class with sets of m <110>-oriented CH(3)NH(3)SnI(3) perovskite sheets separated by iodoformamidinium cations. Whereas the m = 2 compound is semiconducting with a band gap of 0.33 +/- 0.05 electron volt, increasing m leads to more metallic character. The ability to control perovskite sheet orientation through the choice of organic cation demonstrates the flexibility provided by organic-inorganic perovskites and adds an important handle for tailoring and understanding lower dimensional transport in layered perovskites.  相似文献   

13.
对虾在不同的环境条件和养殖模式下具有不同的生长特性,这是进行对虾高效养殖管理的重要依据之一。为探明半集约化土池养殖模式下凡纳滨对虾(Litopenaeus vannamei)的生长特性,2009年5~8月,在广东省电白县的滩涂土池半集约化养殖区,对两个半集约化养殖土池(P1、P2)的凡纳滨对虾的生长参数(全长、体长和体重)进行了养殖全过程的采样测量和数据分析。结果表明:(1)两个土池养殖的凡纳滨对虾的体长(L)与体重(W)均呈显著的幂函数关系,分别为(P1)W=0.016 L2.8935(R2=0.989,P<0.01)、(P2)W=0.0127 L3.0292(R2=0.9911,P<0.01);其生长拐点分别出现在第124 d和128 d;(2)对虾全长(QL)和体长呈明显的线性关系,分别为(P1)QL=0.8319 L+0.2577(R2=0.9997)、(P2)QL=0.8679 L-0.0434(R2=0.9977);(3)体长、体重的von Bertallanffy生长方程分别为(P1)Lt=17.6955(1-e-0.0095(t-12.2421))、Wt=65.2846(1-e-0.0095(t-12.2421))2.8935,(P2)Lt=16.8567(1-e-0.0104(t-21.1781))、Wt=66.0607(1-e-0.0104(t-21.1781))3.0292。  相似文献   

14.
以皇家嘎拉苹果试管苗叶片为试材,采用正交试验设计,研究了氮形态比例(NH4+∶NO3-)、6-BA浓度、NAA浓度对叶片再生不定芽的影响.结果表明:3因素对叶片再生不定芽影响的顺序依次为:氮形态比例(NH4+∶NO3-)>NAA浓度>BA浓度,其中氮形态比例对叶片再生不定芽的影响达到显著水平.3因素水平的最佳不定芽再生组合为:氮形态比例(NH4+∶NO3-)=2∶0,6-BA 2.0 mg/L,NAA 0.1 mg/L的MS培养基.在氮形态比例(NH4+∶NO3+)=2∶0的基础上,进行6-BA、NAA小梯度筛选,结果显示,皇家嘎拉苹果试管苗叶片再生不定芽较高再生频率的培养条件为:6-BA 2.0 mg/L,NAA 0.15 mg/L的改良MS培养基.  相似文献   

15.
[目的]探讨温度和盐度对栉江珧耗氧率(OR)和排氨率(NR)的影响。[方法]设置5个温度梯度和5个盐度梯度,测定温度和盐度对栉江珧OR和NR的影响。[结果]在18~34℃范围内,栉江珧单位体重OR和NR均随温度升高而增加,分别为260.82~585.90μg/(g·h)和26.32~42.19μg/(g·h),OR和NR与温度的相关方程分别为:ORT=-16.14lt^2+197.58t+89.29l(R^2=0.9738);NRT=-0.6981t^2+8.4677t+17.792(R^2=0.9733):在21~41盐度范围内,栉江珧单位体重OR和NR先随盐度增加而降低,在盐度31时达最小值,然后随盐度增加而升高,其变化分别为:575.82~734.40μg/(g·h)和36.78~54.45μg/(g·h),0R和NR与盐度之间的相关方程分别为:ORs=37.929s^2一214.27s+867.6(R^2=0.9872);NRs=3.5442s^2-19.748s+62.08(R^2=0.9461);表明在正常盐度下,贝体能量消耗较低。[结论]温度和盐度对栉江珧OR和NR均有显著影响,  相似文献   

16.
杉木种源地理位置的数学模型   总被引:13,自引:2,他引:11  
<正>杉木种源研究始于一九五七年。20多年来,不少专家致力于杉木种源的研究工作。地理种源试验的重要目的之一:通过种源试验来合理区划种源区域和种子调拨界限,但是由于种源试验规模和数量总是有限的。为了达到上述地理种源试验的目的,就必须研究种源与地理位置的关系。在研究杉木种源与地理位置之间的关系过程中,早期的研究多以定性的方式描述其间关系,而近几年来,多用各种数学模型定量地描述其间关  相似文献   

17.
We investigated the soil microbiologic characteristics, and the yield and sustainable production of winter wheat, by conducting a long-term fertilization experiment. A single application of N, P and K (NPK) fertilizer was taken as the control (CK) and three organic fertilization treatments were used: NPK fertilizer+pig manure (T1), NPK fertilizer+straw return (T2), NPK fertilizer+pig manure+straw return (T3). The results showed that all three organic fertilization treatments (T1, T2 and T3) significantly increased both soil total N (STN) and soil organic carbon (SOC) from 2008 onwards. In 2016, the SOC content and soil C/N ratios for T1, T2 and T3 were significantly higher than those for CK. The three organic fertilization treatments increased soil microbial activity. In 2016, the activity of urease (sucrase) and the soil respiration rate (SRS) for T1, T2 and T3 were significantly higher than those under CK. The organic fertilization treatments also increased the content of soil microbial biomass carbon (SMBC) and microbial biomass nitrogen (SMBN), the SMBC/SMBN ratio and the microbial quotient (qMB). The yield for T1, T2 and T3 was significantly higher than that of CK, respectively. Over the nine years of the investigation, the average yield increased by 9.9, 13.2 and 17.4% for T1, T2 and T3, respectively, compared to the initial yield for each treatment, whereas the average yield of CK over the same period was reduced by 6.5%. T1, T2, and T3 lowered the coefficient of variation (CV) of wheat yield and increased the sustainable yield index (SYI). Wheat grain yield was significantly positively correlated with each of the soil microbial properties (P<0.01). These results showed that the long-term application of combined organic and chemical fertilizers can stabilize crop yield and make it more sustainable by improving the properties of the soil.  相似文献   

18.
微尾鼩种群数量变动及其预测   总被引:8,自引:0,他引:8  
根据南充市防疫站1976-2002年和廖文波等2003年9月-2004年8月的鼠形小兽的调查和监测资料,对该地区优势种群微尾鼩(Anourosorexsquamipes)种群数量变动及预测进行了分析。6个时期内微尾鼩种群数量变化在室内生境不具有周期性(s<0.5);室外生境具周期性(s> 0. 5); 1a有6月和11 -12月2次数量高峰,未成年组(Ⅰ)微尾鼩相对密度冬季最高,春季最低,成年Ⅱ组(Ⅲ)夏季最高,冬季最低;利用回归分析法建立了微尾鼩种群成亚比、雌性成亚比和雄性成亚比提前2个月预测种群密度的3个回归方程:Y=0.167X-4.065;Y=0.148X-2.754;Y=0.142X-1.830,发现种群密度的预测值与实测值基本吻合。  相似文献   

19.
不同基质对小叶赤楠生长的影响   总被引:1,自引:0,他引:1  
为缩短小叶赤楠出圃时间,采用3种不同栽培基质,研究其生长态势及光合日变化趋势。结果表明:蛭石+泥炭(体积比为1∶1,T1)处理小叶赤楠的株高、地径和冠幅最大,分别为45.80、0.68、29.20cm,蛭石+泥炭+黄泥(1∶1∶1,T2)处理的次之,分别为41.20、0.59、23.10cm,蛭石+黄泥(1∶1,T3)处理的最小;3个处理下小叶赤楠光合日变化趋势基本一致,呈双峰曲线,中午有明显的午休现象,日均净光合速率表现为T1>T2>T3。蛭石+泥炭作栽培基质小叶赤楠长势最好,出圃最早,但考虑生产成本,推广使用蛭石+泥炭+黄泥作为栽培基质。  相似文献   

20.
In order to improve the yield of β-mannase and to investigate the rules of fermentation production, a high-yield β-mannase producing strain, Bacillus licheniformis HDYM-04, was used to investigate the kinetics models based on the optimal fermentation conditions: HDYM-04 strain was fermented at 37℃ for 30 h with agitation speed at 300 r/min and aeration rate at 3 L/min in a 5 L fermenter, the initial addition amount of konjac flour was 2%(w/v), the initial pH of medium was 8.0, and the inoculum concentration was 6.7%(v/v). Three batch fermentation kinetic models were established(cell growth kinetic model, substrate consumption kinetic model,product formation kinetic model) bases on Logistic and Luedeking-Piret equations.To be specific, cell growth kinetic model wasdX dt=0.431X(1-X15.522), substrate consumption kinetic model was-dS dt=1.11dX dt+0.000 2dP dt+0.000 8X, and product formation kinetic model wasdP dt=133.1dX dt+222.87X. The correlation coefficients R2of the three equations were 0.990 21, 0.989 08 and 0.988 12, respectively, which indicated a good correlation between experimental values and models. Therefore,the three equations could be used to describe the processes of cell growth, enzyme synthesis and substrate consumption during batch fermentation using B. licheniformis strain HDYM-04. The establishment of batch fermentation kinetic models(cell growth kinetic model, substrate depletion kinetic model, product formation kinetic model)could lay the theoretical foundation and provide practical reference for the application of HDYM-04 in fermentation industry.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号