Biological Nitrogen Fixation by Legumes - Nitrogen Management in Crop Production - page 305

TABLE 7.8 (continued)
Grain Yield (kg ha − 1 ) of 15 Dry Bean Genotypes as Influenced by N + Rhizobium
and Genotype Treatments

Genotype 0 kg N ha − 1 0 kg N ha + Inoculant Inoculant + 50 kg N ha − 1 120 kg N ha − 1

BRS Ametista 2351.86abc 2468.85cdef 2892.65bc 3543.70abc

Diamante Negro 2077.90bcd 1939.33f 2774.75bc 2482.90e

Corrente 1950.66cd 3147.90ab 2818.08bc 3574.98abc

BRS Valente 2283.88abc 2144.57ef 2771.79bc 2853.02cde

BRS Grafite 2130.06bc 2162.26ef 2604.50c 2656.54de

BRS Marfim 2318.51abc 2852.73abcd 3315.85ab 3822.57ab

BRS Agreste 1714.38d 2677.33abcde 2953.39bc 3152.47bcde

Average 2171.53d 2584.22c 2900.05b 3254.31a

F-Test

Year (Y) *

N + inoculant (N) **

Y × N **

Genotype (G) **

**

Y × G

**

N × G

**

Y × N × G

CVY (%) 5.88

CVN (%) 8.86

CVG (%) 10.77

Source: Adapted from Fageria, N. K. et al. 2012. Response of dry bean genotypes to nitrogen and rhizobia under field con-
ditions. Paper presented at the Soil Fertility Meeting, 17-21 September 2012, Maceio, Brazil, Brazilian Soil
Science Society/Federal University of Alagoas, Brazil.
*,**Significant at the 5% and 1% probability levels, respectively. Means followed by the same letter in the same column do
not differ significantly at the 5% probability level by Tukey's test. Average values are compared in the same line.

the overall increase in grain yield was 5% at 0 kg N ha −1 + inoculant treatment, 12% at the inocu-
lant + 50 kg N ha −1 , and 24% at 120 kg N ha −1 treatment compared to control treatment.
The average values of 2 years showed that the increase in grain yield across 15 dry bean
genotypes compared to control treatment was 19% at 0 kg N ha −1 + inoculant treatment, 34% at
inoculant + 50 kg N ha −1 , and 50% at 120 kg N ha −1 . From the grain yield data, it can be concluded
that inoculation improved the grain yield of dry bean genotypes but the increase was much higher
when N was added. Hence, inoculation alone is not sufficient to achieve maximum yield of dry
beans grown in Brazilian Oxisol and chemical N fertilization is essential. An improvement in dry
bean yield with the addition of N has been reported by Soratto et al. (2004) and Pelegrin et al.
(2009). These authors reported that dry bean produced maximum grain yield with the addition of
130 kg N ha −1 in conventional cultivation and 182 kg N ha −1 in the conservation or no-tillage system.
Silveira and Damasceno (1993) recommended 72 kg N ha −1 to achieve the maximum grain yield of
dry bean. The improvement in grain yield of dry bean with the inoculation of seeds with Rhizobium
tropici was also reported by Pelegrin et al. (2009) in a Brazilian Oxisol. However, the yield was
20% higher when 160 kg N ha −1 was added compared to inoculation treatment. These authors also
reported that the maximum yield of dry bean was obtained with the addition of 119 kg N ha −1 . The
grain yield varied from year to year, and this variation may be related to the variation in environ-
mental conditions (Fageria, 1992).