I - --ii

134
Data in Tab. 5 emphasize the importance of an adequate mineral nitrogen
supply in the medium in case the Cicer Rhizobium happens to be absent or too
sporadic in the soil. The experiment was conducted at Tel Hadya during 1979-80
on a field where the native rhizobial count was rather low. The soil had an
available phosphorus (Olsen's extractable P) of 7.5 ppm in the top 15 cm and 4.5
ppm in the 15- to 30-cm soil layer. The available potassium content was 438 and
425 ppm K in the two respective layers. The pH was 8.3 and the soil was poor in
organic carbon content. It was evident from a visual evaluation of the crop that it
suffered from nitrogen deficiency in all the treatments where artificial inoculation
with CicerRhizobium was not done, except in the treatment which received
120 kg fertilizer nitrogen per hectare. Nodulation studies at the preflowering
stage, when the symptoms of nitrogen deficiency were quite conspicuous, revealed
that in the absence of inoculation, the nodulation was extremely poor
(Tab. 5). The total number of leaves that senesced by that stage was also much
higher in those treatments but reduced considerably vhen inoculation was done
or fertilizer nitrogen was applied. More than 50% of the leaves produced by the
preflowering stage had senesced by that time because of nitrogen deficiency in
uninoculated plots. This reflected in reduced total shoot phytomass and ultimately
in poorer yields. Inoculation was as effective as the application of 120kg N/ha
in increasing the yield (Tab. 5).
Other than nitrogen, the mineral nutrient that is most likely to become limiting
under field conditions in the region is phosphorus. Although chickpeas seem to
Table 5
Effect of fertilizer application and inoculation with chickpea Rhizobiurnon shoot dry matter yield at
the preflowering stage, and grain and straw yield at maturity in winter-planted chickpea ILC 1929
at Tel Hadya, 1979-80.
At preflowcring stage
Treatments Nodules/plant No. of leaves/plant Shoot Yield (kg/ha) at maturity
Number Dry wt. Total Senesced Dry wt. Grain Straw
(mg)
(g/plant)
Control 0.4 74 45.0 20.5 0.85 650 1150
50 kg P 20/ha (P) 1.1 111 47.4 29.2 1.08 840 990
60 kg K 20/ha (K) 0.9 137 50.6 24.9 1.23 960 1020
Inoculation () 14.8 195 53.7 11.7 1.49 1180 1780
I + P 17.8 241 53.8 14.2 1.50 1100 1480
1+ K 18.3 248 59.9 16.4 1.75 1000 1500
1 + P + K 18.5 303 61.9 14.6 1.93 910 1520
120 kg N/ha + P + K 0.6 51 51.4 15.8 1.24 980 1460
LSD (5%) 5.73 132.8 N.S. 6.51 0.61 262 391