GroundwaterGroundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock become completely saturated with water is called the water table.
Soil salinitySoil salinity is the salt content in the soil; the process of increasing the salt content is known as salinization. Salts occur naturally within soils and water. Salination can be caused by natural processes such as mineral weathering or by the gradual withdrawal of an ocean. It can also come about through artificial processes such as irrigation and road salt. Salts are a natural component in soils and water. The ions responsible for salination are: Na+, K+, Ca2+, Mg2+ and Cl−.
Accessory fruitAn accessory fruit is a fruit that contains tissue derived from plant parts other than the ovary. In other words, the flesh of the fruit develops not from the floral ovary, but from some adjacent tissue exterior to the carpel (for example, from receptacles or sepal). As a general rule, the accessory fruit is a combination of several floral organs, including the ovary. In contrast, true fruit forms exclusively from the ovary of the flower. Accessory fruits are usually indehiscent, meaning fruits that do not split open to release seeds when they have reached maturity.
Deficit irrigationDeficit irrigation (DI) is a watering strategy that can be applied by different types of irrigation application methods. The correct application of DI requires thorough understanding of the yield response to water (crop sensitivity to drought stress) and of the economic impact of reductions in harvest. In regions where water resources are restrictive it can be more profitable for a farmer to maximize crop water productivity instead of maximizing the harvest per unit land.
Crop residueCrop residues are waste materials generated by agriculture. The two types are: Field residues are materials left in an agricultural field or orchard after the crop has been harvested. These residues include stalks and stubble (stems), leaves and seed pods. Good management of field residues can increase efficiency of irrigation and control of erosion. The residue can be ploughed directly into the ground, or burned first. In contrast, no-till, strip-till or reduced-till agriculture practices are carried out to maximize crop residue cover.
Water potentialWater potential is the potential energy of water per unit volume relative to pure water in reference conditions. Water potential quantifies the tendency of water to move from one area to another due to osmosis, gravity, mechanical pressure and matrix effects such as capillary action (which is caused by surface tension). The concept of water potential has proved useful in understanding and computing water movement within plants, animals, and soil.
TranspirationTranspiration is the process of water movement through a plant and its evaporation from aerial parts, such as leaves, stems and flowers. Water is necessary for plants but only a small amount of water taken up by the roots is used for growth and metabolism. The remaining 97–99.5% is lost by transpiration and guttation. Leaf surfaces are dotted with pores called stomata (singular "stoma"), and in most plants they are more numerous on the undersides of the foliage.
Peak waterPeak water is a concept that underlines the growing constraints on the availability, quality, and use of freshwater resources. Peak water was defined in 2010 by Peter Gleick and Meena Palaniappan. They distinguish between peak renewable, peak non-renewable, and peak ecological water to demonstrate the fact that although there is a vast amount of water on the planet, sustainably managed water is becoming scarce. Lester R.
FloricultureFloriculture is the study of the efficient production of the plants that produce showy, colorful flowers and foliage for human enjoyment and the human environment. It is a commercially successful branch of horticulture and agriculture found throughout the world. Efficient production practices have been developed over the years, for the hundreds of plant taxa used in the floral industry, increasing the overall knowledge of whole plant biology. Plant breeding and selection have produced tens of thousands of new genotypes for human use.
Center-pivot irrigationCenter-pivot irrigation (sometimes called central pivot irrigation), also called water-wheel and circle irrigation, is a method of crop irrigation in which equipment rotates around a pivot and crops are watered with sprinklers. A circular area centered on the pivot is irrigated, often creating a circular pattern in crops when viewed from above (sometimes referred to as crop circles, not to be confused with those formed by circular flattening of a section of a crop in a field).
