Plant Demand Adapted Fertilization in Organic and Precision …
159
biofertilizer + crop residues/green manure) resulted in a high magnitude of increase
in dehydrogenase activity, microbial biomass carbon and potentially mineralizable
nitrogen (57%), but reduced the metabolic quotient which implied an accumulation
of stable organic C under organic nutrient management [9].
5 Precision Agriculture Versus Organic Agriculture
Both precision agriculture (PA) and organic farming (OF) are solutions aimed at
countering and mitigating the problem arising from chemical fertilizers usage. While
both the approaches achieve this aim, PA is principally centered around improving
nutrient use efficiency, fertilizer savings and reducing environmental foot print of
N. But strategies are needed to ensure fertilizer use efficiency in the short-term and
maintenance of soil fertility in the long term. If soil fertility is to be maintained or
even increased, heavier doses of fertilizers have to be used which will be inevitably
be lost, but if fertilizers are applied in low doses, native sources will be reduced and
soil fertility would deplete at a faster rate. The two approaches are pulling in different
directions and it is therefore necessary to adjust the fertilizer practices over seasons
in such a way so as to strike a balance between the two [19].
Organic agriculture is principally aimed at improving soil and plant produce
quality. OA has an in-built element of environmental safety by avoiding emissions
and other concerns associated with fertilizer N usage. But OA generally lacks the
potential for a short-term on-the-go reaction especially with respect to fertilizer application. Further on, in low external input sustainable organic farming, nitrogen, the
key nutrient for agricultural production, is mainly provided by symbiotic legumeRhizobium N 2 fixation, a process that is already related to site-specific conditions
as well as small quantities of organic manure, that delivers plant-available N also
strongly in accordance with site-specific conditions for mineralization. Integrated
nutrient management (INM) strives for the middle ground where both the aims of
PA and OF on fertilizer use efficiency, high yields and soil quality are achieved.
Organo-mineral fertilization has the advantages of both nutrient supply in sufficient quantities and efficiency associated benefits. In Europe, organic fertilizer products have to conform to new EU fertilizing products regulations (FPR) effective June
2022 [3]. New regulation will include all kinds of fertilisers such as biostimulants,
industry by-products, mineral and organic fertilisers and more. For marketing as one
declared source of primary nutrients it has to contain 2.5% N or 2% P or 2% for K.
For more than one declared source, minimum 1% each of NPK and total 4%. An
organo-mineral fertilizer shall be a co-formulation of one or more inorganic fertilisers
and one or more materials containing organic carbon and nutrients of solely biological origin. It may contain peat, leonardite and lignite, but no other material which is
fossilized or embedded in geological formations and shall have minimum 7% organic
matter and shall not contain more than 16% N as ammonium nitrate. Minimum N,
P and K content for sole sources are same as above except that of the 2.5% N (of
which at least 1.0% is as organic N. And for organo-mineral NPK solid mixtures,
159
biofertilizer + crop residues/green manure) resulted in a high magnitude of increase
in dehydrogenase activity, microbial biomass carbon and potentially mineralizable
nitrogen (57%), but reduced the metabolic quotient which implied an accumulation
of stable organic C under organic nutrient management [9].
5 Precision Agriculture Versus Organic Agriculture
Both precision agriculture (PA) and organic farming (OF) are solutions aimed at
countering and mitigating the problem arising from chemical fertilizers usage. While
both the approaches achieve this aim, PA is principally centered around improving
nutrient use efficiency, fertilizer savings and reducing environmental foot print of
N. But strategies are needed to ensure fertilizer use efficiency in the short-term and
maintenance of soil fertility in the long term. If soil fertility is to be maintained or
even increased, heavier doses of fertilizers have to be used which will be inevitably
be lost, but if fertilizers are applied in low doses, native sources will be reduced and
soil fertility would deplete at a faster rate. The two approaches are pulling in different
directions and it is therefore necessary to adjust the fertilizer practices over seasons
in such a way so as to strike a balance between the two [19].
Organic agriculture is principally aimed at improving soil and plant produce
quality. OA has an in-built element of environmental safety by avoiding emissions
and other concerns associated with fertilizer N usage. But OA generally lacks the
potential for a short-term on-the-go reaction especially with respect to fertilizer application. Further on, in low external input sustainable organic farming, nitrogen, the
key nutrient for agricultural production, is mainly provided by symbiotic legumeRhizobium N 2 fixation, a process that is already related to site-specific conditions
as well as small quantities of organic manure, that delivers plant-available N also
strongly in accordance with site-specific conditions for mineralization. Integrated
nutrient management (INM) strives for the middle ground where both the aims of
PA and OF on fertilizer use efficiency, high yields and soil quality are achieved.
Organo-mineral fertilization has the advantages of both nutrient supply in sufficient quantities and efficiency associated benefits. In Europe, organic fertilizer products have to conform to new EU fertilizing products regulations (FPR) effective June
2022 [3]. New regulation will include all kinds of fertilisers such as biostimulants,
industry by-products, mineral and organic fertilisers and more. For marketing as one
declared source of primary nutrients it has to contain 2.5% N or 2% P or 2% for K.
For more than one declared source, minimum 1% each of NPK and total 4%. An
organo-mineral fertilizer shall be a co-formulation of one or more inorganic fertilisers
and one or more materials containing organic carbon and nutrients of solely biological origin. It may contain peat, leonardite and lignite, but no other material which is
fossilized or embedded in geological formations and shall have minimum 7% organic
matter and shall not contain more than 16% N as ammonium nitrate. Minimum N,
P and K content for sole sources are same as above except that of the 2.5% N (of
which at least 1.0% is as organic N. And for organo-mineral NPK solid mixtures,