Key Technical Points for Water Management in Pollution-Free Ponkan Mandarin Cultivation
Water Management in Pollution-Free Ponkan Mandarin Cultivation
Water management for ponkan mandarin trees requires timely irrigation when water is needed and timely drainage during floods, so that the root system has no standing water. Irrigation water must be free of pollution and should meet the requirements of NY/T5016.
1. Irrigation
(1) The effect of water on the growth and fruiting of ponkan mandarin
Water accounts for 80%-85% of ponkan mandarin fruit and more than 60% of branches, leaves and roots. Water plays a key role in the tree's nutrient uptake, transport, maintenance of cell expansion, transpiration, photosynthesis and other physiological processes. Because annual rainfall is unevenly distributed in ponkan mandarin production areas, ponkan mandarin trees should be irrigated when they need water.
(2) Water requirement pattern of ponkan mandarin
Ponkan mandarin has different water requirements at different growth stages throughout the year and follows a transpiration water consumption pattern. Transpiration water consumption is lowest from December to February of the following year, gradually rises after March, and peaks in July-August. Air temperature is positively correlated with transpiration (r=0.9165). Leaves draw water from the fruit for evaporation.
(3) Irrigation amount
The best way to determine the irrigation amount is to first measure the soil water content and then calculate it using the following formula.
Irrigation water = 667 x soil bulk density x root depth x [0.8 x (field maximum water holding capacity - soil water content before irrigation)] (cubic meters/mu)
(4) Irrigation timing
It is too late to irrigate only after ponkan mandarin leaves begin to curl. The specific irrigation timing is commonly determined by methods such as measuring leaf transpiration, soil water content and the daily change in fruit diameter.
Standards for when soil needs irrigation: sandy soil
1. Irrigation
(1) The effect of water on the growth and fruiting of ponkan mandarin
Water accounts for 80%-85% of ponkan mandarin fruit and more than 60% of branches, leaves and roots. Water plays a key role in the tree's nutrient uptake, transport, maintenance of cell expansion, transpiration, photosynthesis and other physiological processes. Because annual rainfall is unevenly distributed in ponkan mandarin production areas, ponkan mandarin trees should be irrigated when they need water.
(2) Water requirement pattern of ponkan mandarin
Ponkan mandarin has different water requirements at different growth stages throughout the year and follows a transpiration water consumption pattern. Transpiration water consumption is lowest from December to February of the following year, gradually rises after March, and peaks in July-August. Air temperature is positively correlated with transpiration (r=0.9165). Leaves draw water from the fruit for evaporation.
(3) Irrigation amount
The best way to determine the irrigation amount is to first measure the soil water content and then calculate it using the following formula.
Irrigation water = 667 x soil bulk density x root depth x [0.8 x (field maximum water holding capacity - soil water content before irrigation)] (cubic meters/mu)
(4) Irrigation timing
It is too late to irrigate only after ponkan mandarin leaves begin to curl. The specific irrigation timing is commonly determined by methods such as measuring leaf transpiration, soil water content and the daily change in fruit diameter.
Standards for when soil needs irrigation: sandy soil