What conditions are needed for navel orange cultivation? A detailed explanation of environmental requirements
SummaryThe soil thickness must be above 1m; sandy loam or heavy loam is best. The orchard requires convenient drainage and irrigation, a leeward and sunny position, ample sunlight and convenient transportation. Generally, hills, mountains, flat land or sandy beach land can all be used for planting. In areas where navel oranges are grown, the annual rainfall must be above 1000mm, the pH value of the soil is best controlled between 5.5-6.5, the annual average temperature must be between 18-22°C, and the annual sunlight duration must reach about 1200-2200 hours.
1. Temperature requirements
Navel oranges begin to sprout in spring when the daily average temperature stabilizes at 12.8°C, and the most suitable daily average temperature for their growth is 23-29°C.
2. Light requirements
Navel oranges have strong shade tolerance, but the duration of light can affect the yield of navel oranges. If there is insufficient light, the growth state of the navel orange tree, the number of fruits set, and the coloring degree of the fruit will all be relatively poor. In areas where the annual sunlight hours reach 1200-2200 hours, navel oranges can grow and develop normally.
3. Rainfall
Navel oranges are best planted in areas where the annual rainfall reaches above 1000mm; sufficient rainwater can enable navel oranges to grow better.
4. Soil requirements
The soil thickness cannot be less than 0.8m, and is best above 1m. Sandy loam, heavy loam and similar soils are best for planting; light clay and heavy clay are both unsuitable for planting.
The pH value in the soil should be controlled between 5.5-6.5. If the pH value is lower than 4.8 or higher than 8.5, it will affect the growth of navel oranges. The soil must contain 3-5% organic matter; within the root absorption range, the organic matter content must reach 2-3%, and at minimum cannot be lower than 1.2%. The available phosphorus in the soil must at minimum not be lower than 0.05%, and should at least be above 0.08%. The available potassium content must be above 0.8%, and at minimum cannot be lower than 0.5%. The hydrolyzable nitrogen content must be above 10-30 mg/100 g.
5. Temperature requirements
In areas where navel oranges are grown, the annual rainfall should be around 1600mm, the average temperature around 18-22°C, the absolute minimum temperature cannot be lower than minus 5°C, the average temperature in January cannot be lower than 7°C, the annual average effective accumulated temperature of ≥10 C should be around 5500-6500 C, the relative humidity in the air should be controlled at around 70-80%, the annual sunlight duration of around 1800 hours is most suitable for navel orange growth, the frost-free period throughout the year must be more than 280 days, and during the fruit ripening period, the temperature difference between day and night must be above 10°C.
6. Orchard selection
In addition to meeting the above requirements, there must also be convenient drainage and irrigation, a sunny and leeward position, a slope below 25%, and convenient transportation. Planting on hills, mountains, flat land or sandy beach land, or in places above the maximum flood water level, can also be done for navel oranges. If the orchard is prone to frost damage and wind damage, 3-5 rows of protective forest belts should be planted around the perimeter.
When planting navel oranges on relatively steep hilly terrain, it is best to build embankment points. According to the designed row spacing, measure out the contour lines at a ratio of 0.2%:40.3%, then build them into terraced fields that climb upward, requiring the outer side to be high and the inner side low, and dig bamboo-joint ditches below the inner terrace wall to store and drain water.
If planting in farmland, because the groundwater level is relatively high, water is likely to accumulate during the rainy season, which will affect the growth of navel oranges. Therefore, when planting navel oranges in farmland, the method of deep ditches and high beds should be adopted, and drainage ditches should be opened well within the field.
To ensure land for grain production, it is best to choose hills or sloping land for planting fruit trees.