Abstract: Phosphorus (P) is an essential element, and the majority of animal feed phosphate is derived from phosphate rock that is a non-renewable resource. Current global P reserves may be depleted in 50–100 years. This poses the challenge of securing future P supply for the global animal feed industries. Currently, nutritionists formulate diets with substantial safety margins to guarantee that animals do not become P deficient. Excessive dietary P concentrations increase, not only the cost of diets, but also P excretion and pollution of the environment. We contend that understanding P bioavailability is central to the sustainable use of this mineral in animal agriculture. Poultry accounts for approximately 50% of animal feed phosphate consumption worldwide and for this reason we use the meat chicken or broiler as a case study to explore the nuances of P bioavailability. We conclude that, to tackle the challenge of dietary P bioavailability, cooperative research on a global scale is needed to standardise measurement procedures in order to produce a robust and reliable database which can be used by nutritionists to formulate diets to meet the bird’s P requirements precisely. Achievement of this goal will assist endeavours to sustain the global supply of phosphorus.
Abstract: In this study, responses of rice under drought stress correlating with changes in chemical compositions were examined. Among 20 studied rice cultivars, Q8 was the most tolerant, whereas Q2 was the most susceptible to drought. Total phenols, total flavonoids, and antioxidant activities, and their accumulation in water deficit conditions were proportional to drought resistance levels of rice. In detail, total phenols and total flavonoids in Q8 (65.3 mg gallic acid equivalent (GAE) and 37.8 mg rutin equivalent (RE) were significantly higher than Q2 (33.9 mg GAE/g and 27.4 mg RE/g, respectively) in both control and drought stress groups. Similarly, the antioxidant activities including DPPH radical scavenging, β-carotene bleaching, and lipid peroxidation inhibition in Q8 were also higher than in Q2, and markedly increased in drought stress. In general, contents of individual phenolic acids in Q8 were higher than Q2, and they were significantly increased in drought stress to much greater extents than in Q2. However, p-hydroxybenzoic acid was found uniquely in Q8 cultivars. In addition, only vanillic acid was found in water deficit stress in both drought resistant and susceptible rice, suggesting that this phenolic acid, together with p-hydroxybenzoic acid, may play a key role in drought-tolerance mechanisms of rice. The use of vanillic acid and p-hyroxybenzoic acid, and their derivatives, may be useful to protect rice production against water shortage stress.
Abstract: The success of precision agriculture relies largely on our ability to identify how the plants’ growth limiting factors vary in time and space. In the field, several stress factors may occur simultaneously, and it is thus crucial to be able to identify the key limitation, in order to decide upon the correct contra-action, e.g., herbicide application. We performed a pot experiment, in which spring wheat was exposed to water shortage, nitrogen deficiency, weed competition (Sinapis alba L.) and fungal infection (Blumeria graminis f. sp. tritici) in a complete, factorial design. A range of sensor measurements were taken every third day from the two-leaf stage until booting of the wheat (BBCH 12 to 40). Already during the first 10 days after stress induction (DAS), both fluorescence measurements and spectral vegetation indices were able to differentiate between non-stressed and stressed wheat plants exposed to water shortage, weed competition or fungal infection. This meant that water shortage and fungal infection could be detected prior to visible symptoms. Nitrogen shortage was detected on the 11–20 DAS. Differentiation of more than one stress factors with the same index was difficult.
Abstract: Research has proven that, at a national scale in Cameroon, arable crop production is either declining or stagnant. In the face of these trends, governments, local and international organizations, communities and peasant farmers have developed adaptation options to sustain arable production and reduce poverty. Given this general context, and based on population perceptions and four study sites in the Southwest region of Cameroon, this study aims at verifying current trends in arable production and farmers’ adaptation options based on their indigenous knowledge. These analyses are based on the administration of 200 questionnaires and two focus group discussions (FGDs). The data were analysed using SPSS version 20 in which frequencies, percentages and means were calculated. In addition, the chi-squared statistical test of goodness of fit was calculated and the stated hypothesis was validated accordingly. The FGDs were analysed through verbatim transcriptions and with the aid of the context analysis software, Wordstat 7. The results show that current yields (2010–2014) in all the study sites are declining due to deforestation, poor governance, inadequate access to farm inputs such as fertilizers, increased economic opportunities elsewhere and a breakdown of cultural practices, while 10 years (2000–2010) previously, they had been increasing. It has also been found that the main adaptation options/coping mechanisms reported by the respondents in order of highest frquencies are: expansion of farm size, help from relatives and dependents that live on the farm, supplemental occupations or livelihood diversification and usage of organic fertilizers. From the chi-squared test, the alternate hypothesis that, “there is some difference between population proportions for different adaptation options or coping mechanisms” is validated.
Abstract: The study assesses international competitiveness, profitability, output supply and input demand of maize production using a farm survey data of 165 farmers from two major maize growing areas (i.e., Dinajpur and Lalmonirhat districts) of northwestern Bangladesh. Results revealed that maize production is globally competitive and, therefore, can successfully substitute its import. Maize production is also profitable at the farm level (Benefit Cost Ratio = 1.21) with no adverse influence of farm size on yield and profitability. Maize farmers are also responsive to changes in market prices of inputs and outputs. A 1% increase in maize price will increase output supply by 0.4%. The most dominant driver of maize supply and other input demands is land. A 1% increase in available land will increase maize supply by a substantial 3.9%. In addition, landless laborers will benefit through an increase in hired labor demand when land area increases. Policy implications include investments in R&D, tenurial reform to consolidate land holding and smooth functioning of the hired labor market in order to increase maize production and profitability in Bangladesh.
Abstract: Residues from animal husbandry are one of the major greenhouse gas (GHG) emission sources in agriculture. The production of biogas from agricultural residues can reduce GHG emissions through an improved handling of the material streams such as manure storage. Additionally, biogas can substitute fossil energy carriers in the provision of heat, power, and transport fuels. The aim of this work is to estimate the manure potential for biogas production in Germany under the consideration of the farm size of livestock production. In Germany, cattle and pig farming is of major relevance with more than 130,000 farms throughout the country. To unlock the biogas potential of manure, the low energy density of manure, depending on the dry matter content, needs to be considered, meaning that biogas installations need to be built close to the manure production on the farm site. This not only results in a high number of biogas plants, but also due to the wide range of farm sizes in Germany, a huge number of very small biogas plants. Small biogas installations have higher specific investment costs. Together with the relatively low methane yields from manure, costs for power generation would be very high. Co-substrates with higher methane yield can lower the costs for biogas. Thus, the use of a co-substrate could help to use small manure potentials. Biogas plants with the necessary minimum size of 50 kWel installed power could be established at farms representing 12% of all cattle and 16.5% of all pigs respectively in Germany. Using excrement from pigs, farms representing 16.5% of the total amount of pigs could establish a biogas plant. The use of manure in combination with energy crops can increase the size of biogas plants on a farm site significantly. At cattle farms, the share would increase to 31.1% with 40% co-substrate and to 40.8% with 60% co-substrate. At pig farms, the share would increase to 36% if co-substrates were used.