Management Practices to Improve Nitrogen Use Efficiency in Crop Plants - Nitrogen Management in Crop Production - page 342

TABLE 8.4
Optimal Base Saturation for Important Annual Crops Grown on Brazilian Oxisols

Type of
Experiment

Plant Part
Measured

Base
Saturation (%) Crop Species Reference

Common bean Field Grain yield 60 Fageria and Santos (2005)

Common bean Field Grain yield 69 Fageria and Stone (2004)

Upland rice Field Grain yield 40 Fageria and Baligar (2001)

Common bean Field Grain yield 70 Lopes et al. (1991)

Corn Field Grain yield 59 Fageria (2001)

Soybean Field Grain yield 63 Fageria (2001)

Upland rice Field Grain yield 50 Lopes et al. (1991)

Upland rice Field Grain yield 30 Sousa et al. (1996)

Common bean Field Grain yield 71 Fageria and Stone (2004)

Corn Field Grain yield 60 Raij et al. (1985)

Wheat Field Grain yield 60 Lopes et al. (1991)

Soybean Field Grain yield 60 Raij et al. (1985)

Cotton Field Grain yield 60 Raij et al. (1985)

Sugarcane Field Cane yield 50 Raij et al. (1985)

Soybean Field Grain yield 61 Gallo et al. (1986)

Source: Adapted from Fageria, N. K. 2001. Pesq. Agropec. Bras. 36:1419-1424; Fageria, N. K., and V. C. Baligar. 2001.
Commun. Soil Sci. Plant Anal . 32:1303-1319; Fageria, N. K., and A. B. Santos. 2005. Influence of base satura-
tion and micronutrient rates on their concentration in the soil and bean productivity in cerrado soil in a no-tillage
system. Paper presented at the VIII National Bean Congress, Goiânia, Brazil, 18-20 October 2005; Fageria, N.
K., and L. F. Stone. 1999. Acidity management of cerrado and varzea soils of Brazil. Santo Antônio de Goiás,
Brazil: EMBRAPA Arroz e Feijão Document No. 92; Gallo, P. B. et al. 1986. Rev. Bras. Ci. Solo 10:253-258;
Lopes, A. S., M. C. Silva, and L. R. G. Guilherme. 1991. Soil acidity and liming. Technical Bulletin 1, São
Paulo, Brazil: National Association for Diffusion of Fertilizers and Agricultural Amendments; Raij, B. V. et al.
1985. Fertilizer and lime recommendations for the State of São Paulo, Brazil. Technical Bulletin 100, Campinas,
Brazil: Agronomy Institute; Sousa, D. M. G., L. N. Miranda, and E. Lobato. 1996. Evaluation methods of lime
requirements in cerrado soils. Cerrado Center of EMBRAPA Technical Circular 33, Planaltina, Brazil: Cerrado
Center of EMBRAPA.

biomass, total root length, root surface area, root number, and root volume, while it increased the
root diameter and Na + /K + ratio. Further, these authors found that rice seedlings accumulate sig-
nificant amounts of osmolytes, most abundantly in response to alkaline treatment, probably in an
attempt to cope with cellular damages from the stress.
Soil salinity and alkalinity can be reduced by adopting many soil and plant management prac-
tices. Management practices that can improve crop yields and consequently nutrient use efficiency
by crop plants grown on salt-affected soils are use of soil amendments to reduce the effect of salts,
the application of farmyard manures to create favorable plant growth environments, the leaching of
salts from the soil profile, and the planting of salt-tolerant crop species or genotypes within species
(Fageria, 2014). The addition of fertilizers, especially potassium, may also help in reducing salin-
ity effects and improving nutrient use efficiency. The maintenance of an internal positive turgor
potential of plants exposed to saline conditions is an important factor for maintaining growth. This
is accomplished by the uptake of ions, chiefly K + , Na + , and Cl − , as well as by synthesizing organic
metabolites. Potassium is the most abundant cation in the cytoplasm, and, in glycophytes, it plays
an important role in osmotic adjustment (Marschner, 1995). Thus, the application of high K + fer-
tilization might enhance the capacity for osmotic adjustment of plants growing in saline habitats.
Planting salt-tolerant crop species or genotypes within species is an attractive, economical, and