An Error Correction Modeling (ECM) of the Determinants of Deforestation in Nigeria

Abstract

Persistent deforestation is one of the major constraints to sustainable economic development in Nigeria. This study used the Error Correction Mechanism (ECM) to determine the economic factors influencing deforestation. The data were national aggregates collected from several secondary sources for 1961-2000. Data analysis showed that there were at least 7 cointegrating vectors in the estimated model. Also, the dynamic unrestricted short-run parameters of cereal cropland growth rates (0.564), tuber cropland growth rates (-1.961), permanent cropland growth rate (22.136), tuber yield (0.126), livestock population (-2.156), human population (-9.214), other land areas (0.281), agricultural Gross Domestic Product (0.156), and roundwood production (0.684) had significant impact on deforestation (p < 0.05). The study recommends that efforts to address further deforestation should include enforcement of laws guiding the cutting of forest trees and research development to ensure development of crop hybrids that are resistant to environmental Stress, among others.     

保护地栽培土壤锰毒的矫正

模拟玻璃温室、塑料大棚硝酸钙盐积累状况，用辣椒进行盆栽试验，研究土壤锰释放规律及植物锰中毒的矫正方法。试验结果表明：添加硅、镁、铁肥和石灰，对矫正辣椒锰中毒都有一定的效果，而以施石灰法最好。     

人工驯养条件下绿孔雀腿部“船桨状”畸形成功矫正的探讨

人工驯养条件下绿孔雀常常因种源、饲养环境、技术条件等诸多因素导致其腿部畸形的发生。2003～2010年,我们共繁殖绿孔雀120余只,蓝孔雀800余只,其中有19只绿孔雀,100余只蓝孔雀出现"船桨状"畸形,畸形率达到了12%～16%。此类畸形一旦发生,如不及时矫正,1～2 d便会死亡。为此我们对出现该类畸形的个体进行了矫正试验,通过不断改进,最终形成了较为简单、有效的应对方法——用毛线在其跗蹠最下端进行简单的捆绑固定进行牵引矫正,畸形个体一般3～10 min内可行走,10 d左右便可康复。最终有17只绿孔雀,96只蓝孔雀获得康复,康复率达到了90%以上。同时我们还对出现此类情况的野鸭、斑头雁、非洲冠鹤等进行了该项矫正操作,均获得了康复。所以,我们认为这个方法的应用对早成鸟幼雏"船桨状"畸形的矫正是非常可行和有效的,其适用范围是普遍的,可以借鉴和推广。     

根际施肥对防治苹果缺铁黄叶病效果的研究

以山东省德州市为试验地点，对用TL－Fe根系输液法矫正苹果缺铁黄叶病的效果进行了研究，结果表明：TL1根系输液6d后，苹果叶片全铁含量比ck增加104．16％，活性铁含量增加307．61％，14d后叶片全铁和活性铁达到最大值，分别比ck增加了147．35％和393．04％，然后开始下降。TL2处理6d后，苹果叶片全铁和活性铁含量达到最大值，分别比ck增加273．22％和642．14％，然后开始下降。TL1处理苹果叶片花全铁、活性铁、挂果数、座果率分别比ck增加140．79％，137．24％，230．35％和696．56％，但花朵数比ck减少25．18％。TL2处理苹果叶 片花全铁、活性铁、花朵数、挂果数、座果率分别比ck增加157．90％，189．16％，38．21％，214．82％和150．46％。从试验结果来看，两种浓度TL（TL1，TL2）根系输液对矫正苹果缺铁黄叶病均有较好的效果，均可持续一年的时间，但相比较而言，以TL1处理效果更好，也更经济。     

迁安市花生测土配方施肥研究

[目的]为施肥分区和肥料配方提供依据。[方法]采用3414试验方案,安排田间试验。应用养分丰缺指标法和线性分析,确定土壤供肥量和肥料利用率。[结果]地膜花生试验地块土壤供氮量、供磷量、供钾量分别为156、51、72 kg/hm2,土壤氮肥、磷肥、钾肥的利用率分别为62.5%、30.7%和24.3%。裸地花生试验地块土壤供氮量、供磷量、供钾量分别为99、31、47 kg/hm2,土壤氮肥、磷肥、钾肥的利用率为53.8%、22.6%和20.3%。[结论]地膜花生产量比裸地花生明显提高。     

Validation and Correction of MOD15‐LAI using In Situ Rice LAI in Southern China

Abstract

MOD15 are one of the standard science products available from the moderate resolution imaging spectroradiometer (MODIS) instrument on the Earth‐observing system (EOS) Terra platform, launched in December 1999. An important requirement of MODIS science products is that they be rigorously validated. In this study, a site intensive MOD15‐LAI (leaf area index) product validation was conducted in southern China in 2003. Results showed that the differences between in situ rice LAI and MOD15‐LAI change in different rice growth. The differences are larger in booting stage, heading stage, and milking stage, but smaller in tiller stage and maturing stage. Otherwise, results indicate that the MODIS algorithm will underestimate LAI value by about 5–10% in total from 1‐km resolution data over the in situ rice LAI in southern China the mean and standard deviation deviated from MOD15‐LAI are smaller than those of in situ rice LAI. Last, according to different stages of rice growth, corrected models were established, and the corrected MOD15‐LAI matched well with in situ LAI.     

区域容积率对基准地价的影响及修正研究—以河北省滦县为例

容积率是影响地价的重要因素之一,容积率修正系数直接关系到基准地价的评估与应用精度。在综合分析文献的基础上,以河北省滦县为例,分析了区域容积率对地价及基准地价的影响规律,利用高光谱遥感和实地校正等方法确定标准容积率,并找出容积率与其修正系数的关系,建立容积率修正体系的对数模型;验证了容积率对地价的影响规律,同时建立了容积率与土地集约利用程度的关系。     

沭阳县人工与自动土壤水分观测资料对比分析

[目的]客观评估DZN1型自动土壤水分观测仪的监测能力。[方法]采用对比差值、逐步回归等方法,比较分析了2013年1月1日~7月31日沭阳国家农气一级站的人工与自动土壤体积含水量观测数据。[结果]人工观测值略高于自动站观测值,两者在浅层的平均差值最小,变化趋势相当一致;在分析了人工与自动观测值相关系数后,为降低DZN1型自动土壤水分观测仪的系统性误差,获得较准确的订正数据,运用逐步回归法建立了沭阳土壤水分自动站观测资料序列订正模型,并利用该站2014年4月1日~5月31日对比观测资料对其订正效果进行了检验,检验结果显著。[结论]该研究为发挥观测资料的应用价值和气象服务效益提供依据。     

论我国农村公共产品供给的自愿失灵

理论的发展以及各国的实践证明,自愿供给是农村公共产品供给的一种重要方式。利他主义的影响、选择性激励、宗教和文化传统的影响等原因使得个人和一些组织自愿供给公共产品,然而,由于公共利益的局限性、慈善的供给不足、我国非营利组织发展乏力等因素的存在,农村公共产品供给出现了自愿失灵。要矫正这种失灵,主流媒体应大力宣传公益事业,多渠道筹集资金,大力发展非营利慈善组织,采取激励措施促进社会自愿供给。     

Diagnostic techniques for cereals based on plant analysis III. Nutrient element therapy and correction models

Abstract

Quantitative methods as the basis to predict the amount of nutrient to be supplemented to overcome deficiency, diagnosed by using the diagnosis and yield prognosis models, are defined as “Therapy Models.”; These models are developed based on the relationships, at 2.0 g Dry Matter weight (DMw) per hill, of increasing concentration as a function of varying initial concentration of a topdressed nutrient element for varying levels of topdressing, and changes in the concentration of other nutrient elements as a function of increasing concentration of topdressed nutrient. Nitrogen and K therapy models were developed in this study and the procedure for applying these models discussed.

Correction models were developed for N, P and K as an aid to convert the concentrations of these nutrient elements corresponding to the DHw level at sampling to those at the 2.0 g DMw level. This conversion is necessary for the application of diagnostic models on the results of plant analysis.