Agriculture Reference
In-Depth Information
5000
Y = 73,973.66 - 22,714.34X + 1738.80X
2
R
2
= 0.0.9491**
4000
3000
2000
1000
0
4
6
Soil pH in H
2
O
7
5
FIGURE 6.11
Influence of soil pH on the uptake of Mn in the shoot of dry bean plants. **—Significant at the
1% probability level. (Adapted from Fageria, N. K. and V. C. Baligar. 1999.
J. Plant Nutr
. 22:23 -32.)
Fageria and Baligar (2005) studied the influence of N on the uptake of Mn in the shoots of dry
bean plants (Table 6.15). The uptake of Mn was significantly increased with increasing N rates
in the range of 0-200 kg ha
−1
. Nitrogen application was responsible for 88% variation in the Mn
uptake. The positive association of N with Mn was related to the improvement in dry matter produc-
tion of dry bean (Fageria and Baligar, 2005). Xue et al. (2012) reported that applying N at an opti-
mal rate (198 kg ha
−1
) to wheat resulted in a significantly higher grain Zn concentration compared
to the control treatment. For example, grain Zn concentration increased from 21.5 mg kg
−1
in the
control to 30.9 mg kg
−1
with the optimum N supply.
6.3.4 n
ItroGen
versus
I
ron
Among micronutrients, except chlorine, iron is required in higher amounts for the growth and
development of plants. Iron stress (deficiency or toxicity) in crop plants often represents a serious
constraint for stabilizing and/or increasing crop yields. Any factor that decreases the availability of
Fe in a soil or competes in the plant absorption process contributes to Fe deficiency. Iron deficiency
TABLE 6.15
Influence of N on the Uptake of Mn in the Shoot of
60-Day-Old Dry Bean Plants
N Rate (kg ha
−1
)
Mn Uptake (g ha
−1
)
0
43.3
40
115.9
80
156.9
120
153.3
160
222.1
200
361.8
R
2
0.88**
**Significant at the 1% probability level.
