Plant Demand Adapted Fertilization in Organic and Precision …
153
Fig. 1 Relationship between nitrogen uptake by rice at harvest and nitrogen concentration in flood
water two days after fertilization and rice seedlings transplantation (Rao [72])
and losses to 45%. Sulphur coasted urea (SCU) and urea super granules (USG, deep
placed) were effective in reducing peak AN levels to <2 g m
−3 and N losses to 17
and 3% respectively. N uptake efficiency with U(S) was 41%. SCU was ineffective in
improving grain yields but improved N recovery to 58%. USG increased grain yields
only in first year by 20% over U(S) and improved N uptake to 61%. A negative linear
relationship was observed between N uptake by rice at harvest and AN levels in
floodwater two days after fertilization (r = 0.96, Fig. 1) which was recommended as
a simple predictable index to evaluate the use efficiency of applied N fertilizers. Based
on a meta-analysis of 32 studies in China, Linquist et al. [50] reported increase of 5.7
and 8.0% in rice yield and N uptake when Enhanced Efficiency Nitrogen Fertilizers
(EENF) (i.e. nitrification and urease inhibitors, neem, and slow release fertilizers)
were applied. In Bangladesh, deep placement of urea super granules (USG) in rice
was widely popularized and led to 30% reduction in N fertilizer over prilled urea
[69].
The fertilizers, which are able to cater regional soil-crop-stage specific fertilizer
requirements, can be called “Customized Fertilizers”. Customized fertilizers facilitate the application of the complete range of plant nutrients in the right proportion
and to suit the specific requirements of a crop in different stages of growth, and
are more relevant under site specific nutrient management practices. Fortified fertilizers are generally common fertilizers to which one or more specific nutrients have
been added in order to increase their nutrient content and make them more versatile. Three important fortified products included in the Fertilizer Control Order of
Government of India are Zincated urea—2% Zn, Boronated SSP—0.18% B, and
10:26:26 fortified with 0.5% Zn and 0.3% Boron [27]. The Government of India
has introduced a mandatory provision to coat all urea fertilizers with ‘neem’ oil, a
nitrification inhibitor.
153
Fig. 1 Relationship between nitrogen uptake by rice at harvest and nitrogen concentration in flood
water two days after fertilization and rice seedlings transplantation (Rao [72])
and losses to 45%. Sulphur coasted urea (SCU) and urea super granules (USG, deep
placed) were effective in reducing peak AN levels to <2 g m
−3 and N losses to 17
and 3% respectively. N uptake efficiency with U(S) was 41%. SCU was ineffective in
improving grain yields but improved N recovery to 58%. USG increased grain yields
only in first year by 20% over U(S) and improved N uptake to 61%. A negative linear
relationship was observed between N uptake by rice at harvest and AN levels in
floodwater two days after fertilization (r = 0.96, Fig. 1) which was recommended as
a simple predictable index to evaluate the use efficiency of applied N fertilizers. Based
on a meta-analysis of 32 studies in China, Linquist et al. [50] reported increase of 5.7
and 8.0% in rice yield and N uptake when Enhanced Efficiency Nitrogen Fertilizers
(EENF) (i.e. nitrification and urease inhibitors, neem, and slow release fertilizers)
were applied. In Bangladesh, deep placement of urea super granules (USG) in rice
was widely popularized and led to 30% reduction in N fertilizer over prilled urea
[69].
The fertilizers, which are able to cater regional soil-crop-stage specific fertilizer
requirements, can be called “Customized Fertilizers”. Customized fertilizers facilitate the application of the complete range of plant nutrients in the right proportion
and to suit the specific requirements of a crop in different stages of growth, and
are more relevant under site specific nutrient management practices. Fortified fertilizers are generally common fertilizers to which one or more specific nutrients have
been added in order to increase their nutrient content and make them more versatile. Three important fortified products included in the Fertilizer Control Order of
Government of India are Zincated urea—2% Zn, Boronated SSP—0.18% B, and
10:26:26 fortified with 0.5% Zn and 0.3% Boron [27]. The Government of India
has introduced a mandatory provision to coat all urea fertilizers with ‘neem’ oil, a
nitrification inhibitor.