Yoshida - 1981 - Fundamentals of Rice Crop Science

MINERAL NUTRITION OF RICE 133
Table 3.13. Effects of nutrient supply in culture solution on leaf
area, tiller number, dry weight, and nutrient contents in rice. a
Nutrient
supply
Weeks after
transplanting
2 4 6 8 10
Complete
Low N
Low P
Low K
Complete
Low N
Low P
Low K
Complete
Low N
Low P
Low K
Complete
Low N
Low P
Low K
Complete
Low N
Low P
Low K
Complete
Low N
Low P
Low K
Leaf area (cm 2 /pot)
312 2280 4616 5734
266 951 1405 1926
207 834 1298 1377
223 832 1230 2943
Tiller number (no./pot)
5.3 41.0 65.0 65.3
3.8 21.0 26.7 34.0
3.8 21.0 32.7 31.0
3.8 31.0 54.0 53.5
Dry wt (g/pot)
1.45 15.6 49.6 81.4
1.17 7.33 18.5 27.8
1.13 6.41 15.4 27.7
1.21 5.63 16.9 33.3
Nitrogen content (% in leaf blades)
4.64 b 3.33 2.37 2.03
4.32 2.66 1.90 1.66
4.57 4.15 3.51 3.15
4.83 4.18 3.19 3.36
Phosphorus content (% in leaf blades)
0.60 0.38 0.23 0.13
0.63 0.53 0.45 0.43
0.23 0.08 0.05 0.03
0.68 0.50 0.25 0.25
Potassium content (% in leaf blades)
2.8 2.8 2.3 2.1
2.9 2.5 1.9 1.8
2.8 2.4 2.4 1.9
2.0 1.0 0.6 0.5
6008
2206
1701
3980
58.3
23.0
29.3
52.5
133.0
39.6
36.6
51.3
1.96
1.64
3.03
3.47
0.18
0.33
0.03
0.25
1.9
1.9
1.6
0.5
a Yoshida and Hayakawa (unpublished). b Underlines indicate nutrient
content of the complete versus a particular nutrient to be
compared.
synthetic rate are estimated at 2% for N, 0.4% for P 2 O 5 , 1% for K 2 O, 0.4% for
MgO, and 0.5% for SO 3 .
Because of its importance in rice, the relationship between nitrogen and photosynthesis
has been studied by many scientists (Table 3.14).
In general, leaf photosynthetic rate is correlated linearly or curvilinearly with
leaf nitrogen or protein content. The shape of the mathematical form may depend