So, welcome for the lecture 24, that is a organic ah field crop management. So, specially
for the cereal crops we will be discussing. So, last class we discussed about vegetables
ah. So, if you see the organic key input management, especially the nutrient management for the
vegetable crops and the cereal crops ah, the crops response differently ah, you can grow
the vegetable crops with full amount of ah organic nutrient or the required amount of
organic nutrients ah, you can attain the yield levels in case of vegetables ah. Because,
in case of the cereals, there is some ah ah because there the determinant crops, they
require the nutrients at specific growth stages. So, ah having organic fertilizers to meet
the nutrient requirement of the crops at the specific stages, that becomes a cost challenge,
specially for the cereal crops and to meet the ah to ah ah yield potentials ah having
the organic nutrient management also, also a challenge . However, by integrations of
the if the beginning of the organic farming, I can go for the integration of the organic
and the chemical fertilizers. We can we can maintain the yield levels and slowly we can
reduce the use of the chemical fertilizer and fully convert organics. This things will
be discussing in the ah the coming lectures when you go for the transition to organic
farming. So, let us discuss about the ah cereal crops
ah, 2 crops will discussing here rice and wheat how we can have a management of the
rice and wheat crops in organic farming . So, rice is a ah family that is a Poaceae
family say origin of South East Asia climatic requirement know this a the rice is grown
in hot and humid climate. So, it is best suited in regions ah which have the prolonged sunshine’s
and an assured supply of water because, rice is a loving crops. It needs the ah water though
not standing water, but need saturation throughout the growing period growing period .
And the average temperature requires ah for the like periods of the crop ranges from 21
to 37 degree Celsius and at the time of tillering the crop requires higher temperature so that
the tiller formation is better. The temperature required for the flowering stress that remains
less than 30 degree Celsius around 26.5 29.5 degree Celsius. But, at the time of the ripening
or say filling periods, it should be within 20 and 25 degree Celsius. Rice is a short
day plant. Usually, it is grown ah during the monsoon
seasons that is you say Kharif season, say when there is a the day length is a decreasing
trend that flower or the flowering behaviour starts in rice. So, that you say as a short
day plants soil ah rice can be grown in any type of soil that is a bearing soil type . The
major soil groups are ah, say alluvium soils, red yellow, red loamy, laterite, coastal alluvium
, red sandy, mixed red and black and medium and shallow black soils.
. The P h for the rice is range from 5.6 ah 5.5 to 6.5, but it can it can be grown in
wide range of P h or grow in the ah 5 to 8 land preparation.
So ah, you know ah, we grow rice as a 2 type of ah rice ah cultivation system one is called
upland rice that is a direct seeding and the other one is called the ah lowland rice or
the medium land transplanted rice . So, basically direct seeding rice and the transplanted rice,
the 2 system of rice cultivation . Directing seeding rice is usually a followed in the
regions where there is no assured rainfall is available. There is a barriated rainfalls
or the low rainfall regions. And the the places where water cannot be stored
for longer periods , in those locations, those ah places, we can go for the direct seeding.
At this specially of plan ecosystems which unbunded appliance, water cannot be retained
and there we go for the direct seeding rice. But, other other cases, medium land, low land
ecosystems having assured ah ah rainwaters, water can be stored in those cases. We go
for the transplanted ah rice cultivations. So, first we can go for the we can discuss
about the upland rice; the direct seeded rice . So, in this method, the soils are not ah
puddled and there is a only for the either the tillage operation, the primary tillage
secondary tillage is a conventional operation is done to have a loose seed belt, loose soils
for sowing of the seeds. So, that is done by the construction of bunds.
We can have a raise in case of upland ecosystems, we can raise the bunds. So, in there is a
rainfalls. So, the water can. So, you do not allow the run of water . Water can be stored,
one should be compacted and properly sealed with no cracks and holes are there. So, this
will minimize the water loss. So, this way, you can store the water in case of the upland
ecosystem . So, they are we go for primary tillage normally undertaken when the soil
wet enough to allow the field to be ploughed and strong to give the reasonable level of
traction. So, this can be immediately after the and
this can be done after harvest, harvest of the beginning of the next seasons depending
upon the soil moistures and water availability ah that is ploughing is done. So, we do prefer
to have a summer ploughing. If you go for the summer ploughing ah ah, in case summer
ploughing, so the soil is opened as a primary tillage and it can helpful for the storing
of the rain water discharge of the rainwater. Otherwise, they ah if there is no ah n1 ploughed
soil, the water maybe loss as run of the loss. So, ah this type fertilize operations for
the direct seeding . Ah. You can go for the secondary tillage.
As a loose soils, then you can level and sow the seeds. A seeds can be sown in case of
direct seeding as a dry seed it sown and when the the they area receives the rainfall due
to the monsoon rain and the seed can germinate and this sowing should be advised. We, looking
at the monsoon pattern or the rainfall pattern. It should be because, after once the seeds
germinates and they comes to the above the soil surface, emergence takes place and if
there is a dry plough for the unit for 1-week ah, it will affect the crop growth that maybe
complete mortality or the death of the whole crop.
So, so, so this sowing should be done in such a time that, so the crop should get the assured
rainfalls for the establishment ah face at least up to ah ah tillering stage when the
crop tries to establish in case of low land rice or say puddle transplanted rice. So,
this is done where there is a ah rainfall amount sufficient available for the crop growth
and also the the field has a capacity. It can stored water for longer periods.
In that case, you can go for the transplanted rice ah, but if they the other cases where
there is a the shortage of rainfalls, deficient rainfalls abnormalities, we go for the direct
seeding because, if there is a in case of direct seeding when the crop establishes after
tillering stage. If there is a stress, the ah water stress
due to the less rainfalls or the dry soil, the crop can survive the dry soil. But, this
minute happen in case of the transplanted rice. They the transplanted rice is less adaptable
to ah climate variability or the dry soil conditions in there is a dry soil even if
for 1 week, the there may be failure of the crops in case of transplanting condition ah.
So, we go for the puddings, specially the this because of the puddling, because because
when we go for puddling, the land should be ploughed immediately after harvest of the
previous crop. Preferably, with ah mould board plough that breaks hard pan and keeps the
soil loose . And this facilitates ah ah sowing of the operations ah to completed on time.
Soon after pre monsoon showers 1 or 2 summer ploughing also done for this in April May
can keep the land ready for timely operation. . Then, you go for the puddling puddling means
ah, by ploughing the land or clear of (Refer Time:08:11) with the standing water we we
input the water in the field and go on ploughing of the regions. So, that causes the destruction
of the soil aggregates, let say destruction of the soil , structure soil structure. We
are destroying the soil structure though puddling operations.
So, that means, the puddling causes physical destruction of soil aggregates irrigations
and non-capillary pore space as a result of which individual soil particles gets segregated
and dispersed and just say leaving ah this soil ah mass into a soft puddle . In this
case, when 2 puddling operations as we go for puddling the soil particles gets dispersed
from each other. . So, if you as you see, if you take a ah
ah soil soil soils ah, soil in a beaker and mixing in the water certain amount of water.
Mix it thoroughly and leave it for some time you can see. So, there is settling of soil
particles the initially the sand settles the being the heavier particle settles fast followed
by the sealed particle the next heavier settles and finally, the clay particles that close
the pore spaces. So, by puddling operation the pore spaces are closed.
So, that creates an impermeable layers . So, due to that, so there is no downward movement
of water. That means, that checks the depopulation of water which helps in maintaining standing
water in the field. So, that is why, when you go for a puddling
operations, usually it maintains standing water can be ah maintained the field and ah
during puddling as water is maintained . It is less pruned to as a less ah the weed infects
because, weed growth will be checked due to continuous maintenance of standing water and
the puddle transplanted rice and yield wise. If you can see the compare direct seeding
and the proto transplanting yield wise, the proto transplanting rice ah, they have the
higher yield as compared to direct seeding. Because, there is a some soil chemical property
changes in the puddle conditions as compare to direct seeding there are many nutrients
that available. Because of the reduced conditions created
in case of puddling standing water is maintained . So, that helps in many macro and micro nutrients
and the response to external of the nutrients is less in case of proto transplanting as
compare to direct seeding . So, after the puddling you can level the field and you can
go for the planting of the rice . The advantages of transplanted rice means,
it helps in maintaining optimum plant population. Unlike the direct seeding, there may be sparse
populations , but in case we are planting the with with unified uniform spacing, so
we can maintain proper populations and that facilitate the uniform healthy crops stand
an equal opportunity to utilize space, light, nutrients and water.
So, that is one reason why the the healthy crop, they stands uniform stand population
. So, that also enhances the yield of the crop in case of the trans plant rice, then
weeds are substantially killed in this process of puddling and subsequent submergence as
you maintain. So, there is a less weed growth. So, less completion of weed growth crops,
the crops gets better nutrients that we also that helps in enhancing the yield of the crops
in the in trans planting as compared to direct seeding crops . So, this is an conventional
method transplanting; also equal just say, we go for the another method system of rice
intensification, usually for organic farming .
We do a recommend to go for the S R I system of rice intensifications ah. Because, here
we have the we use young seedling as compared to conventional the seeding is it 25 days.
But, in case of the ah organic systems, we use the young seedling the quick intensification
seeding and the spacing is the wider spacing the 25 centimeter 25 centimeter has conventional.
It is 20 to 15 centimeter spacing and when you go for the plantings number of seeding
per hill , we use one seedlings per hill in case of the ah S R I verses 3 to 4 seedling
per hill in conventional and if the water maintenance.
So, you maintain saturation of water in case of the S R I verses plus 5 centimeter or more
than 5 centimeter standing water in conventional . So, ah these are the basic differences in
case of the S R I systems with the ah normal transplanted rice. So, having S R I systems
ah, you are using the young seedling. We have the different ah nursery bare grazing technique
for S R I systems ah. There we can use the as a method of nursery you can say ah there
the seedling can be ready for trans planting within 15 days.
If you delay because the seed the seedling densities around 1 kg per meter square in
case of S R I . So, because of higher seedling density, the seedlings are prepared ah not
on the soil surface and the putting a plastic sheets or polythene sheets or that the seedling
the seedling can a thin layer of soils. And once when the soil is with vermicompost mix
is kept and on that, the seeds are sown. The sprouted seeds around 1 kg per meter squares.
This covered by again thin layer of vermicompost and the sprinkling water is done in order
to avoid any type of water stress so, so that, this seedling should not dry.
So, this is the seedling emergence takes place and within 15 days you should go for the transplanting
if you delay transplanting because there is no sufficient supply of nutrients to the ah
seedlings, but this is grow in a limited soils ah over the plastic sheets and the seedling
becomes the yellow after 15 days. So, we have to go for transplanting and we can use only
1 seedling or maximum 2 seedlings for the in case of the ah, S R I technique and the
spacing is wider to give 25 25 centimeter and this has advantage ah advantage over the
conventional techniques or conventional planting .
Having wider spacing, young seedling is expected to have the better yield as compared to older
seedlings and the wider spacing means, the it it provides the maximum space good space
for a particular seedling 1 or 2 seedling to get the nutrients optimum water and nutrients
for a proper growth and development having 1 seedling or the 2 seedling per hill. So,
that has a more number of pillar formations as compared to the conventional practice where
we are using 3 to 4 seedlings per hill and the spacing is narrow spacing around 20 to
15 centimeter. . So, that way, the S R I system the system
of rice intensification that have the better yield as compared to the conventional practice
and ah ah of course, we are as we are maintaining the saturation water . We are not giving the
standing water while providing the saturation of water and the standing water. In case of
the saturation water, there is a proper exchange of air between the atmosphere and soil surface
and that helps in the better formation of tillers and in S R I.
If you ah, specially during the tiller operations, if you only use 1 centimeter water and ah
use a rotary weeders in the in the inter areas. So, that causes of a aerations in the soils
and the atmosphere that and also that helps in removing the older roots. Older roots are
pruned, they are cut, they are mixed in the soils that helps the formation of the better
root systems. So, by this way, S R I systems having the
less water ah exchange of air in the atmosphere and soil that becomes better that helps in
the more and more tiller formation ah as compared to conventional in conventional you may have
the tiller surround 20 tillers per hill, but S R I the tillers may go up to 30 tillers
per hill. So, that that because of higher tiller formation S R is that, due to the wider
spacing young tillers and the shallow water levels saturations , that helps in more tiller
formations and if tiller formations increases. So, that ultimately leads to more number of
panicles and having the more number of panicles that ha that ah causes in higher yield. So,
the research report has given the variable informations about the enhancement yield in
S R I as compared to conventional practice if you maintain a S R I ah scientifically
and accurately there there will be around 20 percent yield improvement in S R I systems
as compared to conventional practice . And moreover, having the S R I systems , you
are saving the huge amount of seed because, in case of conventional practice, the seed
requirement around 50 kg per hectare. In S R I, this is only 5 kg per hectare . That
way, you can you can minimizing around 80 percent of the seed requirement in S R I systems
as compared to conventional and further also water management.
So, as you are maintaining only saturations no standing water is required standing water
never leads to the improvement in crop yield as we discussed earlier also having standing
water that causes the reduced conditions in the soils and also that that that causes the
ah loss of nitrogen as a relented loses in to loses yield management of fertilizers and
also there is a methane emissions having standing water that causes emission of methane as a
global warming potentials, but maintaining saturations.
So, you can minimize the emission greenhouse gases either from methane or nitrous oxide
from the crop field that way you can minimize the global warming potentials. So, ah ah being
ah in the S R I systems, usually for the organic farming system, you go for system of rice
intensifications, you can minimize your the sheet requirements.
Because, the 80 percent of the sheet requirement can be minimized as compared to conventional
practice as we are using only 5 kg per hectare seed per S R I against 50 kg per hectare in
case of conventional seeds and moreover, the water also you can minimize the water requirement
around 40 percent with maintaining saturations. Only without going for standing water, you
can get the better yield as compared to the conventional practice.
So, this is why, so, system of rice intensification that we are going for the organic farming.
And you can in addition to that, you can go for the ah nutrients managements as transplanted
rice or the direct seedling rice , the you can go for the green manure cultivations ah
when you go for the organic. So, green manures , green manure crop ah of Sesbania aculeata
and Crotalaria juncea. So, that can be taken the 60-day old crop can contribute approximately
100 kg nitrogen per hectare 25 to 30 kg P per hectare and 75 kg K per hectare and this
can meet the requirement of organic crops. So, you can growing the green manure crops.
Before the rice rice and ah the seed rate is around 25 to g 30 kg per hectare of Sesbania
and the sowing time ah last week of April to first fortnight of the May and this is
incorporated ploughed back in the field. So, before when you go for land preparation
ah, when the crop is around 55 to 60 days, because it is a place stages at the vegetable
stages and that can be ploughed back and . At this stage, if you incorporate in the field,
that can be well decomposed in the in the field and the nutrients can be easily available
for the H for the rice crop ah. By doing green manuring, then you can minimize
your the nutrient requirement or the cops because as as you are going for the if you
grow transplanted rice , as you see the this way, you can go for the unprofessional green
manures and during the ah land preparation or the puddling operations, they can be ploughed
back in the soils. And that can be those are this is a well decomposed and succulent very
succulent. And that can be those things can be well decomposed
and also you can use using farm yard manure. The well decomposed farm yard manures we apply
around 50 to 20 tons per hectare which can supply around 75 to 100 kg nitrogen per hectare
35 to 40 kg P 2 O 5 and 75 to 100 kg K 2 O per hectare.
So, FYM should be decomposed by ah you can have the Trichoderma ah species fungus that
can be added also ah to the FYM or a better decompositions. And, it can have a the effect
on the field also by avoiding any insect pest and diseases .
We can go for enriched compost like the various methods of composting for ah nutrient ah ah
enrichment through either rock phosphate, pyrite, microorganism have better quality
with respect to ah N, P and K as phosphate or the dolomite or the mica and the microorganisms
can be least in the compost preparation process. We can have a enriched compost productions
and we can have the Azolla. The inoculation of Azolla bio fertilizer at 7 days after transplantation
of rice crop at 2 tones per hectare in standing water and it is ah growth during the rice
crop are organic matter and nitrogen to the soil. Azolla also can be incorporated at the
time of puddling if rice field at 6 ton per hectare.
Also, we can provide around 25 to 30 kg N per hectare rice crop. I organic farming systems
ah, vermicompost ah, application of vermicompost at 5 ton per hectare can meet the nutrient
requirement. So, what is I if you go for the when I go for the organic farming, specially
as rice, we are discussing is a requires nitrogen. Similar crops they need continuous supply
supply of nitrogen at the critical growth stages for the better growth and development.
Unlike the vegetable crops like a like we discussed potato or the ah that needs more
of potash. You know potash ah the. So, this organic manure
that applied at the beginning and this is slow release unlike the chemical fertilizers
they have fast release and if the nutrients are not taken away crops, the nutrients are
lost. But, organic farming ah, organic nutrients, the slow release decompositions and the slow
mineralization process and the nutrients water list.
They meet the synchrony with the crops demand crop demand and loss is less as compared to
the chemical fertilizers in case of vegetables . As their demand is for potash or the phosphorus,
different nutrients for the ah in case of the ah potato or the tomato.
And those applying the the organic manures at the basal applications and with the slow
mineralization process. They can meet then nutrient requirement during the growth stages
and those crops like your potato tomato vegetables, they are the indeterminate crops means, so
they are the growth facers like vegetatives or the reproductive. They are not synchrony.
Because, the vegetative and the reproductive, they are overlapping, they continues parallelly,
they have the because potato you can see, tomato we do not harvest tomato all the ah
all fields at 1 stage. The harvesting starts from 1 1 stage and it
may continue for 1 or 15 days or 1 month depending upon the fruiting. But, this does not have
this is. Because of the overlapping of vegetative and reproduction stages and this does not
happen in crops like cereals and wheat. When you go for the cereals , rice crop, we do
not harvest in stages. We harvest rice when matures at a particular time; not ah not like
tomato at a as a staggered harvest. Because, the rice is a determinant crops where this
stages are very specific. And that is why, the need and requirement
is also very specific. We meet with the need and requirement at particular growth stages.
So, rice has the different critical stages as you say tillering stage, ah panicle in
sessions and the flowering as we discussed earlier also ah earlier classes we needs and
demand that we hire in case of tillering and panicle in some in addition to the basal basal
leads to the initiation of tillers and if you apply the nutrients or the tillering that
leads to maximum tiller formations and after that, you apply panicle initiations that leads
to maximum grain formations. So, to meet the yield requirement at specific
growth stages ah ah, having the organic either the green manures, as you say, you have to
go for green manures. So, that the the release is very slow and the loss is very less.
Ah. I mean in green manure crops or applying the enriched compost ah or Azolla or the vermin
compost. So, you have to need the huge amounts because, very high to meet the requirement
and in this case, we can also go for the spilt applications ah to meet the requirement. At
least ah in one of the critical stages, we have seen from our experiments. If you go
for the split application of vermicompost, specially at the time of the 50 percent, at
the time of the land preparations or the planting times will and the rest 50 percent ah just
before panicle in sessions. So, the you can maintain the yield level same
as of the chemical fertilizer at the same time the this will have a also the higher
effect for the subsequent crops because, unlike the chemical fertilizer as you apply chemical
fertilizer exactly at the critical stages. So, that boosts the yield of the crop. We
can get the higher higher yield ah, but having the organic fertilizers ah mixing also proper
ah mixing the fertilizers with the with the soils that is very essential to have a better
availability of the nutrients. So, that can be possible only during the basal
or the during the land preparation . That is why, you apply the ah the most of the the
organic fertilizer at the time of land preparations. And moreover, it is a slow release. So, not
like chemical fertilizer nutrients are ah not fast release. Release very slow due to
the slow process of nutritional organic fertilizers and that meets the nutrient requirement of
the crops. So, throughout the ah as per the growth stages and ah that can that that can
avoid the loss ah loss of yield. But, however, for this specially for the rice
crops ah, if see the integrated organic and the chemical 50 50 that ah is giving from
the experiment that giving the best result as compare to the only vermi only organic.
Because, you need the you have to by doing integration of the chemical fertilizers and
organic fertilizers you can minimize the requirement of the vemicompost at the beginning of the
ah organic farming. So, later on, when the soil gets build up
may be after 10 years continuous applications. So, in that case, you can minimize the use
of chemical fertilizer and complete defense upon the organic fertilizers for the rice
productions. So, this is about the then we will discuss about the this is about the um
the green manuring or use of the bio fertilizer Azolla or the vermicompost or the compost
ah in the during the land preparations in the for rice cultivations. Then, we will discuss
how to calculate the the doses of ah nutrients ah for the rice. And also, we will discuss
the the wheat the management of wheat crops ah in the next class.