131application. For example, Singh et al. ( 1977 ) reported that the benefits from fertil-
izer N placed below the seeds were higher than its broadcast application when the
rainfall occurred immediately after planting as compared to when rain was delayed
in wheat.
Application of organic manures in dryland soil may be useful to improve water
holding capacity of soil. For instance, Zhang et al. ( 1982 ) reported that application
of organic manure (7.5 t ha−^1 ) to a dryland soil improved the water storage ~44.7 mm
more in top 2-m soil layer than no manure application. In a similar study, Cheng
et al. ( 1987 ) found 33 mm more water in 2-m soil layer with manure application
than no manure application. Application of synthetic fertilizers along with organic
fertilizers not only enhance the soil nutrients and crop nutrition, but also enhance
soil organic carbon, soil structure, water holding capacity, water use efficiency and
finally the crop yield of crops (Ma et al. 1984 ).
3.6 Balanced Fertilization
Most of the farmers in dryland regions of the world are just focusing on a single
nutrient. Balanced fertilization in dryland crops may be useful to enhance the nutri-
ent use efficiency. In India, several on-farm trials demonstrated that the yield and N
use efficiency of dryland crops were increased by balanced fertilization. The agro-
nomic efficiency of the applied N was enhanced by applying K and P fertilizers, by
10.3 kg pearl millet grain kg−^1 N, 6.7 kg sorghum grain kg−^1 N, and 19.5 kg maize
grain kg−^1 N. The N use efficiency in pearl millet, maize and sorghum was also
enhanced by 6–20 % (Prasad 2009 ). In Bangalore- India, growing the yield and
fertilizer N use efficiency of pearl millet grown on K-deficient red soil was more
with NK application than NP application over time (Vasuki et al. 2009 ). In another
study in northwestern India on loamy sand soil, the growth of pearl millet was sub-
stantially enhanced with K application (Yadav et al. 2007 ). In a study on sorghum,
N application at 40 kg ha−^1 and P application at 13 kg ha−^1 enhanced the grain yield
by 2.5 times more than the farmers’ fertilizer use practice (use of single nutrient
source). In another study, combine application of N and P fertilizers enhanced the
wheat grain yield by 27.4–65.2 % on a P deficient soil (Table 4 ). Likewise, applica-
tion of 50 kg N ha−^1 and 13 kg P ha−^1 improved the castor bean yield by 38 %
against the suboptimal application (10 kg N ha−^1 and 13 kg P ha−^1 ) (Sharma et al.
2007 ).
On a P deficient soil, the yield of wheat was 1125 kg ha−^1 without fertilizer appli-
cation. When, the N was applied at 135 kg ha−^1 , wheat yield was reduced to 975 kg
ha−^1. However, the yield was increased to 2775 kg ha−^1 with the application of 20 kg
ha−^1 P. When both N and P were applied at the same rate together, the yield was
increased to 4495 kg ha−^1 (Li et al. 1978 , 1979 ), which indicated the importance of
balanced fertilization in dryland soils. Several other studies reported increase in N
and P use efficiency and regulation of imbalances between N and P use in dryland
soils due to combine application of N and P (Jin 1989 ; Wu 1989 ). In a study,
Nutrient Management in Dryland Agriculture Systems