Effects of planting dates on growth and nutrient accumulation of carrots in the brazilian semi-arid

Fertilization plays an important role on carrot’s yield, root quality, storage, plant growth and on the environment. It was aimed to evaluate the plant growth and macronutrients accumulation of carrot cultivars as a function of two planting dates, under high temperatures in the Brazilian semi-arid. The experiments were carried out in randomized blocks design, with ten treatments and four repetitions. Treatments consisted of ten carrot cultivars sowed in two Planting dates. The characteristics that were evaluated were: plant growth (plant height, number of leaves, plant dry matter accumulation, mean fresh mass of the root) and macronutrient accumulation (N, P, K, Ca and Mg) in plant, leaves and root. Plant’s mean height ranged from 42.53 cm (Melinda) to 49.25 cm (Nativa); the highest plant dry matter was obtained by BRS Planalto (12.36 g) and Kuronan (12.18 g); the mean number of leaves was the lowest in Melinda and Nativa: 8.64 and 7.64 leaves plant-1. The root’s fresh weight had a significant decrease among the planting dates for the Brasília, Francine and Suprema cultivars. The nutrient accumulation varied accordingly to the planting date and cultivar

An Intercropping Bibliography

This issue was undated. The date given is an estimate.126 pages, 1 article*An Intercropping Bibliography* (Federer, Walter T.) 126 page

Integrated nematode management

This book outlines the economic importance of specific plant parasitic nematode problems on the major food and industrial crops and presents the state-of-the-art management strategies that have been developed to reduce specific nematode impacts and outlines their limitations. Case studies to illustrate nematode impact in the field are presented and future changes in nematode disease pressure that might develop as a result of climate change and new cropping systems are discussed.illustrato

Proceedings of the Workshop on Adaptation of Plants to Soil Stresses

Sustainable production of food and forage with a focus on plant adaptation to stress environments will be a continued priority for developing countries in the future. Since many areas of the world which support substantial human populations are drought prone, such as the subsaharan African zone and others, the primary focus has been on drought. However, one of the greatest restraints to sustainability of agriculture worldwide is the lack of sufficient soil nutrients for crop growth, or other soil constraints such as acidity or salinity which hinder crop production substantially. Optimizing soil fertility or amending acid and saline soils to achieve high production is difficult in areas of low economic stability since inputs are costly or quite often technically not feasible. The other obvious alternative to increase stability in stress areas is by genetic improvement of crops. Dr. Donald L. Plucknett, in a recent lecture on science and agricultural transformations, stated that while not all yield gains in the Green Revolutions can be attributed to plant breeding, it is doubtful such gains would have taken place without the new varieties or hybrids . Development and release of new and improved germplasm is probably the most economic method of technology transfer currently available. According to Dr. Plucknett, most studies indicate about half of yield gains can be attributed to genetic improvements. This statistic is undoubtedly argued in many circles, but regardless of the final figure, gains from genetic improvement are substantial

Water Management for Sustainable Food Production

The agricultural community is face with the challenge of increasing food production by more than 70% to meet demand from the global population increase by the mid-21st century. Sustainable food production involves the sustained availability of resources, such as water and energy, to agriculture. The key challenges to sustainable food production are population increase, increasing demands for food, climate change, climate variability, and decreasing per capita land and water resources. To discuss more details on (a) the challenges for sustainable food production and (b) mitigation options available, a Special Issue on “Water Management for Sustainable Food Production” was assembled. This Special Issue focused on issues such as irrigation using brackish water, virtual water trade, allocation of water resources, consequences of excess precipitation on crop yields, strategies to increase water productivity, rainwater harvesting, irrigation water management, deficit irrigation, fertilization, environmental and socio-economic impacts, and irrigation water quality. The articles in the Special Issue cover several water-related issues across the U.S., Asia, Middle East, Africa, and Pakistan concerning sustainable food production. The articles in this Special Issue highlight the substantial impacts on agricultural production, water availability, and water quality in the face of increasing demands for food and energy

Irrigation Systems and Practices in Challenging Environments

The book Irrigation Systems and Practices in Challenging Environments is divided into two interesting sections, with the first section titled Agricultural Water Productivity in Stressed Environments, which consists of nine chapters technically crafted by experts in their own right in their fields of expertise. Topics range from effects of irrigation on the physiology of plants, deficit irrigation practices and the genetic manipulation, to creating drought tolerant variety and a host of interesting topics to cater for the those interested in the plant water soil atmosphere relationships and agronomic practices relevant in many challenging environments, more so with the onslaught of global warming, climate change and the accompanying agro-meteorological impacts. The second section, with eight chapters, deals with systems of irrigation practices around the world, covering different climate zones apart from showing casing practices for sustainable irrigation practices and more efficient ways of conveying irrigation waters - the life blood of agriculture, undoubtedly the most important sector in the world

Proceedings of the 2012 Canadian Organic Science Conference

The Canadian Organic Science Conference and Organic Science Cluster Strategic Meetings featured leading scientists presenting and discussing current advances in the field of organic and sustainable agricultural practices in Canada and beyond. Information is of interest to both organic and conventional researchers, with research presented in a diverse range of fields, including: soil fertility, quality and health; horticultural and specialty crops; cereal-based cropping systems; livestock productivity, health and welfare; greenhouse production and season extension; food, sustainability and organic systems; social science and organic agriculture; and extension of organic research

Simulation of site-specific irrigation control strategies with sparse input data

Crop and irrigation water use efficiencies may be improved by managing irrigation application timing and volumes using physical and agronomic principles. However, the crop water requirement may be spatially variable due to different soil properties and genetic variations in the crop across the field. Adaptive control strategies can be used to locally control water applications in response to in-field temporal and spatial variability with the aim of maximising both crop development and water use efficiency. A simulation framework ‘VARIwise’ has been created to aid the development, evaluation and management of spatially and temporally varied adaptive irrigation control strategies (McCarthy et al., 2010). VARIwise enables alternative control strategies to be simulated with different crop and environmental conditions and at a range of spatial resolutions. An iterative learning controller and model predictive controller have been implemented in VARIwise to improve the irrigation of cotton. The iterative learning control strategy involves using the soil moisture response to the previous irrigation volume to adjust the applied irrigation volume applied at the next irrigation event. For field implementation this controller has low data requirements as only soil moisture data is required after each irrigation event. In contrast, a model predictive controller has high data requirements as measured soil and plant data are required at a high spatial resolution in a field implementation. Model predictive control involves using a calibrated model to determine the irrigation application and/or timing which results in the highest predicted yield or water use efficiency. The implementation of these strategies is described and a case study is presented to demonstrate the operation of the strategies with various levels of data availability. It is concluded that in situations of sparse data, the iterative learning controller performs significantly better than a model predictive controller

Air pollution and livestock production

The air in a livestock farming environment contains high concentrations of dust particles and gaseous pollutants. The total inhalable dust can enter the nose and mouth during normal breathing and the thoracic dust can reach into the lungs. However, it is the respirable dust particles that can penetrate further into the gas-exchange region, making it the most hazardous dust component. Prolonged exposure to high concentrations of dust particles can lead to respiratory health issues for both livestock and farming staff. Ammonia, an example of a gaseous pollutant, is derived from the decomposition of nitrous compounds. Increased exposure to ammonia may also have an effect on the health of humans and livestock. There are a number of technologies available to ensure exposure to these pollutants is minimised. Through proactive means, (the optimal design and management of livestock buildings) air quality can be improved to reduce the likelihood of risks associated with sub-optimal air quality. Once air problems have taken hold, other reduction methods need to be applied utilising a more reactive approach. A key requirement for the control of concentration and exposure of airborne pollutants to an acceptable level is to be able to conduct real-time measurements of these pollutants. This paper provides a review of airborne pollution including methods to both measure and control the concentration of pollutants in livestock buildings