Leaf dew contributes nutrients to paddies and improves rice growth

Abstract

Leaf dew is an important input in farmland ecosystems, but information regarding the nutrients from leaf dew deposition in paddy fields is scarce. Leaf dew samples were monitored and collected in situ from the Sanjiang Plain paddy experimental station during the rice growing periods in 2008, 2009, and 2010. The pH and essential nutrients [ammonium nitrogen (NH þ 4 ÀN), nitrate nitrogen (NO À 3 ÀN), and phosphorus (P)] in paddy leaf dew were investigated, the nutrients in guttation and condensed dew were distinguished. In addition, the nutrient contributions of foliar fertilizer to Oryza sativa L (rice) were compared with those of leaf dew. The results indicate that the mean pH of leaf dew on rice is 6.3 (n 056), lower than the pH of rain and surface water. Condensed dew contributes about 97.7% of the nitrogen (N) and 95.7% of the phosphorus (P) in paddy leaf dew. Guttation provides a minor part of the N and P in leaf dew. The amount of leaf dewfall is much larger than the volume of foliar fertilization, with the amount of NH þ 4 ÀN, NO À 3 ÀN, and P deposition from leaf dew almost 100 higher than from foliar fertilization. Compared with foliar fertilizer, leaf dew is a natural and potential fertilizer. Leaf dew is an important pathway for nutrient transfer within paddies.

Characteristics of dew events in an arid artificial oasis cropland and a sub-humid cropland in China

“…This is because the temperature gradient was higher for dew formation in Taklimakan Desert, but the atmospheric water vapor concentration was lower. The average of daily dew amount in Luancheng was close to that in the soybean and corn farmlands (0.19-0.30 mm/night) (Yan et al, 2010), less than that in rice paddy field (0.49-0.67 mm/night) (Xu et al, 2013) of Sanjiang Plain. The atmospheric water vapor concentration in rice paddy field was higher.…”

“…Moreover, dew is an important source of water that may significantly influence the physiological status of vegetation and microclimate environment (Xu et al, 2013;Uclés et al, 2014). Although the amount of dew is very small, it is extremely important in arid areas and during dry period in humid areas (Agam and Berliner, 2006).…”

“…The presence of dew on leaves can increase the local humidity and reduce transpiration rate (Barradas and Glez-Medellín, 1999). It promotes photosynthesis and delays the wilting of leaves , promotes the absorption of nutrients (Xu et al, 2013) and increases aboveground growth of plants (Zhuang and Ratcliffe, 2012). Dew can also alter the predawn water potential of leaves (Kim and Lee, 2011) and the isotopic composition of leaf water .…”

“…In all, dew is an important supplement water source in arid and semi-arid areas (Xu et al, 2013), and the frequency of dew events is likely to increase and exert different impacts in different climate areas in the future under the worldwide increasing trend of atmospheric humidity (Dai, 2006;Willett et al, 2007). In this research, two croplands were selected in different climate areas for the purpose of comparison.…”

A novel method for monitoring urban dew condensation and its application

“…Moreover, dew formation can maintain canopy layer moisture and reduce the plant transpiration. Dew provides nutrients (N, P, and K) to plants [2,3]. During dew formation, the small aerosol in the atmosphere is the condensation nucleus and is important in air purification [4]; furthermore, dew can reveal air pollution status and act as an air quality indicator [5,6].…”