Agriculture Reference
In-Depth Information
Application of Active EM-Calcium in Green Agricultural Production — Case Study in Tomato and…
http://dx.doi.org/10.5772/58329
solution (9 meq L
-1
), and with 14 days' low-Ca application, Ca concentration in all plant organs
(leaves, stems and roots) was reduced by approximately 70% compared to control plants; we
reported that 2.0‰ Ca application increased the Ca accumulation in upper leaf, lower leaf,
root, stem to maximum rates of 28.09%, 23.50%, 29.15%, 33.34% compared to no-calcium
treatment, the causes of the difference were probably related to the nutrient supply methods,
calcium supply through roots increased the Ca content of tomato fruits by increasing which
of other organs, while calcium spray on leaves or young fruits increased Ca content of tomato
fruits by changing the Ca migration, the evidence to support this speculation in this study was
that the foliar spray increased the Ca content of fruits but decreased which of leaves. Dong
(2001) guessed that a “Ca-attracted” center was formed in the spray organ when spraying Ca
nutrient (CaCl
2
), Ca
2+
was attracted to the center and then migrated from the center to the organ
which needed Ca most. However, the migration mechanism about Ca migration with exoge‐
nous Ca application needed to be examined by
45
Ca tracing technique (Behling et al., 1989;
Yamauchi et al., 1986).
3. Effects of EM-Calcium on production of flue-cured tobacco
3.1. Materials and methods
3.1.1. Test site
The experiments were carried out in a plastic sheet covered greenhouse from March 2013 to
September 2013 in the Vegetables and Flowers Institute of Nanjing (latitude 31°43' N, longitude
118°46'E), China. The average annual rainfall is about 1106.5mm, with the rainy season from
the end of June to the middle of July, and the average yearly temperature is approximately
15.7℃ and average humidity is about 81%. The soil characters were: pH 5.68, 14.47 g/kg organic
matter, 28.5 mg/kg available P, 153.84 mg/kg available K, 1.3 8g/kg total nitrogen.
3.1.2. Experimental design
K326 was chosen as the flue-cured tobacco plant material, with young plants elaborately
cultivated in made-in-order seedling trays; then they would be transplanted into the lysimeters
when they grew 6 expanded leaves. The planting density was 12 plants per treatment, with
the line spacing of 0.8m and plant spacing of 0.6m. After that, conventional field management
was conducted in the first week.
For simulating the water stress in growing stages, the irrigation amount was designed as
400mm during the whole growth stage. Irrigation waters of root-extending stage, vigorous
stage and maturity stage in this experiment were assigned as 40%, 20%, 40% for the total water
consumption respectively, and they were irrigated 6 times in each growth stage. Tobacco
dedicated fertilizers (provided by the Institute of Guizhou Tobacco Science, N: P
2
O
5
: K
2
O=1:2:3)
were applied according to a proportion of basal dressing: topdressing=7:3, the latency time of
topdressing was 26 days after transplanted.
