Agriculture Reference
In-Depth Information
Y = 725.0935 - 207.6118X + 15.1307X
2
R
2
= 0.9615*
80
60
40
20
0
4
6
7
5
Soil pH in H
2
O
FIGURE 6.9
Influence of soil pH on the uptake of Zn in the shoot of dry bean plants. *—Significant at the
5% probability level. (Adapted from Fageria, N. K. and V. C. Baligar. 1999.
J. Plant Nutr
. 22:23 -32.)
Brazilian Oxisol. Singh and Singh (1985) also reported that as the N supply to rice increased, Zn defi-
ciency was observed. Savithri and Ramnathan (1990) reported that the application of ZnSO
4
increased
the response of rice to urea-N by 400-600 kg grain ha
−1
. It is widely reported in the literature that
N × Zn interaction is very common in crops that respond to N fertilization (Bajwa and Paul, 1978;
Kene and Deshpande, 1980; Kumar et al., 1985; Sakal et al., 1988; Verma and Bhagat, 1990). From
these studies, it was concluded that N and Zn having synergistic interaction and maximum yield could
be obtained with optimum balance between these two nutrients (Aulakh and Malhi, 2005). Data in
Table 6.12 show that the maximum yield of wheat was obtained when N, P, K, and Zn were at adequate
levels. Synergistic N × Zn interactions have been reported to increase the N concentration in different
crop species (Singh and Tripathi, 1974; Hulagur and Dangarwala, 1983; Kene and Deshpande, 1980).
The use of balanced N and Zn improved biological nitrogen fixation in legumes and also amino acids
and proteins in cereals (Dwivedi and Randhawa, 1973; Kene and Deshpande, 1980).
Kutman et al. (2011) reported that Zn uptake by wheat plants enhanced up to fourfold by high N
supply while the increase in plant growth by high N supply was much less. They further reported
that when both the Zn and N supplies were high, approximately 50% of grain Zn was provided by
postanthesis shoot uptake, indicating that the contribution of remobilization to grain accumulation
was higher for Zn. Kutman et al. (2010) and Shi et al. (2010) also reported that the grain concentration
of Zn can be enhanced by increasing the N supply and that Zn and N applications have a synergistic
effect on the grain Zn concentration of durum wheat. Nitrogen nutrition of plants appears to be a crit-
ical component for an effective biofortification of food crops with Zn due to several physiological and
molecular mechanisms, which are under the influence of N nutritional status (Cakmak et al., 2010).
TABLE 6.12
Grain Yield of Wheat (kg ha
−1
) as Influenced by N, P, K, and Zn Levels
N (kg ha
−1
)
P (kg ha
−1
)
K (kg ha
−1
)
0 kg Zn ha
−1
5 kg Zn ha
−1
10 kg Zn ha
−1
0
0
0
1450
1580
1640
50
30
25
2730
2880
3030
100
60
50
3530
3840
4040
LSD (5%)
220
Source:
Adapted from Sakal, R., A. P. Singh, and R. B. Sinha. 1988.
J. Indian Soc. Soil Sci.
36:125-127.
