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In several states of India, where dryland agriculture is being practiced, 73–95 %
of fields were found deficient in S, 62–94 % in Zn and, 70–100 % in B (Sahrawat
et al. 2010 ). The deficiency of Cu has also been reported in some dryland soil of
southern Australia. The cropping intensity is also very decisive factor for determin-
ing the deficiency/toxicity of micro/trace nutrients in dryland soils. The soil analysis
to find the trace nutrients requirement of crops is less satisfactory than the plant
analysis (e.g., leaf) (El-Fouly 1983 ). The Fe deficiency in dryland soils is associated
with the high calcareous nature of dryland soils and crop type. For example, sor-
ghum is sensitive to Fe deficiency (Babaria and Patel 1981 ). In Australia, wheat has
been found to suffer from Cu deficiency (Smith 1983 ).
2.6 Lack of Integrated Nutrient Management Approaches
Lack of integrated nutrient management in dryland soils is another issue which
affects the nutrient use efficiency and the crop productivity. Farmers usually use
chemical fertilizers as source of nutrients which is not as beneficial as an integrated
nutrient management approach may be. Studies have reported decline in crop yield
over time in dryland regions with the continuous use of the chemical fertilizers
(Bekunda et al. 1997 ). The reasons for this yield decline includes (i) higher nutrient
removal by crops than the added nutrients (Scaife 1971 ), (ii) enhanced nutrient
losses through denitrification and volatilization, and (iii) decline in soil organic mat-
ter over time. For example, application of N fertilizer to monocropped sorghum
(with crop residues removed from the field) enhanced the annual soil organic matter
loss from 1.5 % without fertilizer to 1.9 and 2.6 % with moderate and high N rates,
respectively (Pieri 1995 ). In a study, continuous application of chemical fertilizers
decreased the grain yield of finger millet (Eleusine coracana L.) from an average of
2,880 kg ha−^1 during the initial 5 years to 1490 kg ha−^1 by the 19th year of the study
(Gajanan et al. 1999 ).
In China, the excessive use of fertilizer N, inadequate use of K and P fertilizers,
and low use of organic manures are the main reasons for low fertilizer use efficiency
in dryland crops (Yu et al. 2007 ). Most of the farmers in China use ammonium
bicarbonate as main N fertilizer source which has high losses due to ammonia vola-
tilization, and thus has low N use efficiency than urea fertilizer (Wang et al. 2003 ).
3 Strategies for Improving Nutrient Management in Dryland
Agriculture Systems
Nutrient management challenges in dryland crop production systems may be effec-
tively tackled through integrated nutrient and crop management strategies.
Conservation agriculture approach, water conservation, use of slow and controlled
A. Nawaz and M. Farooq