Cassava Yield, Garrification Traits and Economic Returns as Influenced by Different Genotypes in an Ultisol

Field trials were conducted at the University of Uyo Teaching and Research Farm in 2009/2010 and 2010/2011 to evaluate cassava yield, garrification traits, and economic returns as influenced by genotypes grown in an ultisol. Uyo is located between latitudes 4°30' and 5°27'N and longitudes 7°50'E and 80°20'E. The area, which lies within the humid tropical rainforest zone of southeastern Nigeria, has an annual mean rainfall of 2500 mm with a bimodal rainfall pattern, monthly sunshine of 3.14 hours, and a mean annual temperature of 28°C. The experimental site was previously put into cultivation of some arable crops such as fluted pumpkin, okra, and waterleaf before it was fallowed for two years. A randomized complete block design, replicated three times was used. Treatments were 16 cassava genotypes (AR1-82, NR02/0028, NR03/0174, CR12-45, NR03/0211, TMS98/2132, TMS01/1206, TMS01/1368, TMS01/1371, CR36-5, NR02/0007, NR03/0155, AR37-108, TMS01/1412, TMS30572 and local best variety “Obubit okpo”). Results obtained via combined (pooled) analysis of the two seasons indicated that cassava yield differed significantly among the genotypes. NR02/0018 (42.50 t/ha) out-yielded others by 17% - 52% followed by NR 02/0007 (35.42 t/ha), and NR 03/0155 (32.08 t/ha). TMS 98/2132 had the most preferred garrification attributes followed by NR 02/0018, NR 02/0007, and NR03/01155. NR 02/0018 genotype gave the highest economic returns followed by NR 02/0007 and NR03/0155. NR02/0018 superseded others in yield, garrification traits, and economic returns, which is therefore recommended.

经营性公路合理回报测算方法研究

针对经营性公路项目的合理回报目前法律上没有明确规定,社会上各方认识不统一的问题,研究提出了经营性公路合理回报的衡量指标——合理收益率,明确了合理收益率的考核模式,并对确定的考核模式,给出了测算合理收益率区间上限和下限的具体方法。最后,运用提出的测算方法,借助于经营性高速公路项目进行了实证分析。根据研究结果,建议经营性高速公路项目的合理收益率上限值取10.0%,下限值取相应年份的无风险收益率。测算结果为经营性高速公路项目的投资及行业收益监管提供了参考依据。

Analysis of the impacts of socioeconomic factors on hiring an external labor force in tilapia farming in Southern Togo

This study analyzed the financial profitability and the impacts of socioeconomic factors on hiring an external labor force in tilapia farming in Southern Togo.We obtained the primary data from 75 randomly selected tilapia farmers for socioeconomic analysis by a structured questionnaire.Logit regression and return on investment(ROI)were performed to analyze the influence of socioeconomic factors on the decision of tilapia farmers to hire an external labor force and financial profitability of tilapia farming in the study area,respectively.The results indicate that tilapia farming contributes to employment opportunities in the study area.However,the key variables such as economic diversification,farming experience and educational attainment significantly affect the farmers’decision to hire an external labor force in their farms.Furthermore,tilapia farming is a profitable activity based on the positive mean gross margin and mean net farm income.The ROI was 0.31,which implies that a return of USD 0.31 was obtained for the investment of every single dollar.The government must pay more attention by organizing training or re-training workshops for tilapia farmers,which would improve their socio-economic status.

TRANSFORMATION OF AGRICULTURE ON THE LOESS PLATEAU OF CHINA TOWARD GREEN DEVELOPMENT

Loess Plateau of China is a typical dryland agricultural area.Agriculture there has transformed from food shortage toward green development over the past seven decades,and has achieved world-renowned achievements.During1950–1980,the population increased from 42 to 77 million,increasing grain production to meet food demand of rapid population growth was the greatest challenge.Engineering measures such as terracing and check-dam were the crucial strategies to increase crop production.From 1981 to 2000,most of agronomic measures played a key role in increasing crops yield,and a series of policy support has benefited millions of smallholders.As expected,these measures and policies greatly increased crop production and basically achieved food security;but,low per capita GDP(only about 620 USD in 2000)was still a big challenge.During 2001–2015,the increase in agricultural and non-agricultural income together supported the increase in farmer income to5781 USD·yr^(–1).Intensive agriculture that relies heavily on chemicals increased crop productivity by 56%.Steadfast policy support such as"Grain for Green Program"had an overwhelming advantage in protecting the natural ecological environment.In the new era,the integration of science and technology innovations,policy support and positive societal factors will be the golden key to further improve food production,protect environment,and increase smallholder income.

Allocation of maize varieties according to temperature for use in mechanical kernel harvesting in Ningxia, China

The reasonable assessment of maize varieties in different ecological regions can allow temperature resources to be fully exploited and reach the goal of high yield and efficiency and is thus an important direction of modern maize development in China.In this study,a logistic power nonlinear growth model was used to simulate the accumulated temperature required for kernel dehydration to moisture contents of 25%,20%,and 16%for various maize cultivar,which were divided into six types based on the accumulated temperature required for kernel dehydration to a moisture content of 25%.The relationship between the yield of maize cultivars and the accumulated temperature required for kernel dehydration to a moisture content of 25%was found to follow a unary function model.Changing the planted maize variety was found to increase economic returns by more than 7000 RMB/hm2 in Ningxia,Northwest China.Under the conditions of mechanical grain harvesting,economic benefits can be further increased by means of selecting high yields and fast-dehydrating varieties,selling when the grain dehydration is below 16%.A better way to achieve grain dehydration to a moisture content below 16%is to postpone the harvest date as much as possible rather than drying after the harvest at physiological maturity.The areas of various types of maize varieties can be dehydrated to moisture contents of 25%,20%,and 16%were marked.Based on the distribution of heat resources in different regions of Ningxia from the normal sowing date to October 31 before winter irrigation,the appropriate cultivars for various regions in the province were determined based on production benefits.Therefore,in different areas of Ningxia,selecting suitable maize varieties according to temperature resources can reach a high yield and mechanical kernel harvesting,and ultimately obtain higher economic benefits.

Carbon payments in the Guanzhong–Tianshui region to control land degradation

Carbon trading and carbon offset markets are potential policy options for mitigating greenhouse gas emissions and climate change. A price on carbon is expected to generate demand for carbon offsets. In a market-based framework, the carbon price should be high enough to compensate for opportunity costs. We studied a highly-modified agricultural system in the Guanzhong–Tianshui economic region of China that is typical of many temperate agricultural zones in western China. We quantified the economic returns from agriculture and from carbon plantings(both monoculture and ecological plantings) under five carbon-price scenarios. The mean carbon sequestration is 34 Mg·hm^(–2)·a^(–1), and the average annual payment increased to 1146 CNY·hm^(–2) at a medium carbon price of 50 CNY·Mg^(–1) CO_2^(–e). Thus, areas of high priority for conservation and restoration may be restored relatively cheaply in the presence of a carbon market.Overall, however, less carbon is sequestered by ecological plantings(i.e., mixed native trees and shrubs) compared to agriculture.