Water, Nutrients, Radiation and CO2 Use Efficiency of Bulb Crops: A Review

Abstract

World’s natural resource will be pressured by population increment that is to achieve high food production through intensive farming. Bulb crops are among largely produced which are characterized by a shallow root system and underground vertical shoots. They are also cool season crops, and their growth and production are influenced by water, nutrients, radiation and carbon-dioxide. Factors that determine their water use efficiency are tillage, stage of the crop, evapotranspiration, irrigation, soil types and elevated co 2 . Nutrient use efficiency of bulbs also influenced by factors like soil factors, fertilizer factors, plant factors, agronomic consideration, biological consideration and climate factors. Nitrogen, phosphorus and potassium are the major consumed nutrients of bulbs. Radiation use efficiency of the bulbs also the key determinant of photosynthesis, photorespiration and respiration. Indicators of radiation use efficiency of bulbs are dry matter production, leaf area index and specific leaf area, ground cover, radiation interception and absorption, maintenance respiration of bulbs and dry matter partitioning. Another essential substrate for photosynthesis of bulb crops is co 2 and the main factors that determine co 2 use efficiency of bulbs are temperature and light. So as different studies indicated that for best production of bulb crops water, nutrient, radiation and co 2 use efficiency of them and the respective determinant factors should be considered and optimized.