The effect of an intelligent surface drip irrigation method on sorghum biomass, energy and water savings

Over the last few decades, precipitation has decreased as a result of climate change. This change increases crop water requirements, while irrigation water is wasted because of improper irrigation scheduling. Soil moisture sensors could be used to improve irrigation scheduling and save both water and energy. The objective was to study the energy and water savings, and the gross margin achieved, when using an intelligent surface drip irrigation method on sorghum bicolor (L.) Moench. In the years 2008 and 2009, a study was conducted at the farm of the University of Thessaly, Central Greece. A Class A evaporation pan and an automated frequency domain reflectometry soil moisture sensor were used for irrigation scheduling. Two treatments in four replications were organized in a randomized complete block design: (1) pan surface drip irrigation (PSDI100) and amount of water equal to 100 % of the daily evapotranspiration (ETd), as determined by a Class A evaporation pan, and (2) automated surface drip irrigation (ASDI100) and amount of water equal to 100 % of the ETd, as determined by an automated soil moisture sensor. The mean dry biomass production and the gross margin were greater in the PSDI100 treatment. The fully automated treatment remained profitable despite the high first costs. The mean water saving was 12.5 %, while the mean energy saving was 12.4 %, and the irrigation water-use efficiency was higher in the ASDI100 treatment

History of Use and Trade of Agarwood

Aromatics originating from the resin-infused infected wood of the Aquilaria and Gyrinops genera have distinct and valued fragrances. Resin formation occurs as a response to internal injury and/or infections in the stems of the agarwood tree. The incenses and perfumes that are produced from agarwood have been valued for centuries and used by many cultures for spiritual, opulent, and aphrodisiac purposes. Agarwood is highly revered in the seminal texts of Hinduism, Christianity, Buddhism, and Islam. As early as 1400 B.C.E., agarwood was described as a fragrant product in Sanskrit texts, and in 65 B.C.E., Dioscorides detailed several medical applications for agarwood. Knowledge of human-induced agarwood formation was recorded in China as early as 300 C.E., where it was known that cutting into a tree would lead to a color change in its internal tissues within a year of the injury as a consequence of resin development. There is historical evidence of international trade in agarwood between the producing (tropical southeastern Asia) and consuming (Middle East, India, China, and Japan) regions of the world. Agarwood has been consumed primarily as incense with the burning of wood chips directly or as an important ingredient for powdered incense blends. The aromatic qualities of agarwood are influenced by the species and variety of the two genera, geographic location, its branch, trunk and root origin, length of time since infection, and methods of harvesting and processing. The subtle but numerous variations in agarwood properties led to the development of systems for product classification and description in several consumer countries. This paper reviews the uses and trade of agarwood and its social, political, and economic significance in human history