1253.3 Nutrient Application on the Basis of Soil Analysis
For estimating the deficiency and fulfill the crop nutrient needs in dryland regions,
there is a need of careful soil analysis (Peverill et al. 1999 ). The soil nutrient status
may change over time due to continuous nutrient uptake by the crops. For example,
regular application of P is needed in the cereal–legume rotation in dryland soils
(Ryan et al. 2008b) to harvest good crop yield. Likewise, K application (based on
soil test and crop needs) to dryland soil may help to boost the crop productivity by
improving root growth, enhancing the water use efficiency and regulating the sto-
matal closure. Soil and plant analysis may be helpful to correct the deficiency and
toxicity of micronutrients (Reuter and Robinson 1997 ). For this, the most economi-
cal way to correct the micronutrient deficiencies in dryland soils is the small addi-
tion of these micronutrients to the base fertilizers.
3.4 Integrated Nutrient and Crop Management Approaches
Integrated use of inorganic and organic fertilizers in dryland regions may be the
most beneficial than their separate use. For instance, in a 5-years study, Bouraima
et al. ( 2015 ) reported that combined application of fertilizer with manure reduced
runoff losses and prevented the soil erosion. Losses of total N and P were also
reduced by 41.2 and 33.3 % with combine application of manure with chemical
fertilizer. In another study, implementation of advanced moisture conservation prac-
tices and the optimum use of inorganic and organic fertilizers were beneficial for
improving crop yields in dryland soils (Hadda and Arora 2006 ). Combine use of
organic manures, crop residues and green manures in dryland soils together with
mineral fertilizers may help build up macronutrient pool in these soils for sustaining
the crop productivity on long term basis (Bationo et al. 1997 ). In dryland soils, the
grain production of cereals is more when organic and the mineral fertilizers are used
in combination (Palm et al. 1997 ). For instance, combine use of N with organic
fertilizer enhanced the wheat grain yield by 10–41 %, and precipitation use effi-
ciency by 10–42 % (Table 3 ). In Sudan, combine application of manure with chemi-
cal fertilizers sustained the productivity of sorghum (Sedogo 1993 ). Supplying
50 % of the recommended fertilizer through crop residues and 50 % through the
loppings of a N fixing tree (Leucaena leucocephala) enhanced the yield of sorghum
by 31–87 %, against the application of 25–50 kg N ha−^1 through inorganic fertilizer
source (AICRPDA 1999 ). The fertilizer is one of the most expensive input in dry-
land farming in China, and its increased use has already resulted in the 100 % incre-
ment in crop yield in rainfed regions. In China, the farm yard manure was regarded
as main source of nutrients before 1970s in dryland agriculture. The fertilizer use is
still increasing in dryland agriculture in china, but the ratio of N to P used by most
of the famers is more against the recommended ratio (1:0.3) for dryland crops (Tong
et al. 2003 ).
Nutrient Management in Dryland Agriculture Systems