Impact OF Resource
Conservation (Zero Tillage) Technology on Wheat Production
Agriculture contributes almost
24.6% of GDP of Pakistan. In addition, it provides employment
to approximately 52% of total labor force of the country and
more than 70% of the population is directly or indirectly
dependent upon agriculture. Besides meeting ever-growing food
and fiber needs of the nation, agriculture sector contributes
about 75% of foreign exchange earnings of the
Agriculture development is, therefore, imperative for
meeting the needs of food and fiber of the nation besides
ensuring sustainable economic growth of Pakistan.
Wheat is staple food crop of the nation and the Punjab
province contributes about 80% of its total production in the
country. The per capita consumption of wheat
(140kg/capita/annum) is the highest amongst dietary intake
pattern of an average Pakistani. Rice consumption stands
second with an average of about 17kg per capita per annum.
Unfortunately, each year government is
compelled to import wheat in order to fulfil the domestic
needs. Foreign exchange requirements for the purpose are
mounting for every subsequent year. For example, import of
285,000 MT wheat in 1970-71 amounting to Rs.62.7 million was
increased to 1,887,000 MT in 1996-97 with foreign exchange
loss of Rs. 14.22 billion. During 1997-98 the import of wheat
has further increased to
4,050,000 MT. It is to be noted that import of wheat has
increased 6.6 times in quantities but corresponding foreign
exchange depletion is 227 times greater.
Technological Breakthrough is Imperative
It is alarming to note that there is no marked increase in per
capita availability of food grains and any disaster in
agricultural sector, at any time, cannot cope with the
tremendous population growth rate. A major breakthrough in the
agriculture sector is, therefore, required to avert possible
catastrophic situation expected in near future. Possible
strategies are: either to increase cropped area, or to
increase productivity per unit of land, or to apply
combination of both the alternatives.
The strategy for bringing more area under cultivation is,
nevertheless, very expensive as compared to that of increasing
productivity per unit of land. Furthermore, there is great
potential for increasing crop yields, which can be achieved in
considerable shorter span of time and with much less financial
costs. Proper management of production factors such as land,
labor, capital and other water and non-water inputsare
the key to meet this end. Mechanization of
agricultural operations is an important aspect, which needs to
be, adopted alongwith bringing improvements in use of other
inputs e.g. water, fertilizer, seed, herbicides, and
Steps for efficient/adequate use of other water and non- water
inputs as well as various farming operations are required to
be initiated at the same time. Adoption of appropriate
Irrigation Agronomic practices for on farm water management
alongwith use of right type of agricultural equipment to
ensure timely and proper establishment of wheat can help in
achieving higher levels
of productivity in the province.
Wheat Cultivation Problems in Paddy Country
In irrigated areas, about 90 percent of wheat is cultivated
after harvest of rice and cotton. Accordingly, there is
short window of time available for land preparations for
establishing wheat due to late maturing long grain rice
varieties. It normally takes 2-3 weeks for rice fields to
become workable for land preparations due to antecedent
moisture. In addition, reduced day length
and sunshine decrease soil and ambient temperature at the
time, which delays planting of wheat in paddy tracts.
It has been established that delay in planting of wheat after
20th November results in reduction of potential wheat yield by
about 1 % per day. Moreover, farmers cultivate land often
without achieving suitable seedbed conditions for planting
wheat, which esults in poor crop yields.
Another factor hindering
achieving optimum wheat yield in paddy areas is that wheat
seed is generally broadcasted into soil clods due to poor land
preparations. This leaves unevenly distributed seed in the
soil profile leading to much reduced plant emergence. A
technological breakthrough is, therefore, imperative to
address all these problems in wheat production to meet
requirements of ever increasing population.
Resource Conservation Technology (RCT)
Technology (Zero Tillage, Zero Till or Minimum Tillage) is a
special technique of establishing crops without tillage and
seedbed preparations. The implement used for this purpose is
known as direct drill, which is capable to seed through the
residue cover, and provides a firm seed soil contact. The
technique has been found useful specially for raising Rabi
crops in the rice harvested fields where uncertain rains and
excessive soil moisture do not permit timely sowing of wheat.
Beside this, the technology also saves expenditure involved in
seedbed preparations. Post sowing weed control in Conservation
Tillage requires use of herbicides similar to the conventional
sowing system. This technique of sowing wheat has been found
useful is now followed extensively in many countries like USA.
Australia, Brazil. South Africa and New Zealand.
Promotion of Conservation Tillage Technology in Pakistan
A seed drill, which can sow wheat in paddy fields, was earlier
developed at Massey University, New Zealand. The seed drill
referred to as "zero tillage drill" was fabricated in Pakistan
with assistance from New Zealand experts in collaboration with
Pakistan Agricultural Research Council (PARC), Islamabad.
Initial research experiments with conservation tillage
technology were carried out by PARC in mid 1980's. These
proved quite successful, but because of lack of funding and
other resources, its wide scale replication could not be
promoted. Limited field trials for wheat establishment with
this technique were undertaken in the rice growing areas
ofOECF/Japan assisted OFWM-III Project in Gujranwala/Gujrat
region in the Punjab and Larkana/Shikarpur districts in Sindh
in 1996. Five drills were procured under the project for the
purpose. Results of these trials indicated that conservation
tillage method of planting wheat resulted in 28% higher yields
compared to those with conventional method. In addition, a
saving of about Rs.750/acre was noted in production costs as a
result of no land preparations.
Zero Tillage technology was demonstrated on large area in
rice-wheat system of Punjab during Rabi 1997 and 10 zero
tillage drills were arranged for the purpose. Under OECF/Japan
assisted OFWM Program 10 Field Teams were organized to drill
about 1,000 acres in Gujranwala, Lahore, Sialkot,
Sheikhupura, Gujrat, and Mandi Bahaudin districts. The OFWM
staff provided drills, technical know-how, and training free
of charge to the farmers. Where farmer did not own tractors,
the Field Teams provided drill and tractor with a charge of Rs.
100 per acre.
Prior to the planting of wheat crop, training sessions for the
OFWM staff and farmers were arranged at Area Team level. In
these sessions, the problems of low wheat yield particularly
late planting after rice were highlighted. The need for zero
tillage drill, its handling (calibration for seed and
fertilizer), and actual operation in the field were
demonstrated to each team.
Follow up activities were also
arranged to carry out the operation smoothly and adoption of
other agronomic practices, particularly application
ofweedicides etc. A brochure on zero tillage wheat production
technology was prepared in English as well as Urdu and was
distributed among field staff and farmers.
In November, 1997 at the request of Pakistan Agricultural
Research Council (PARC), Islamabad, Government of New Zealand
financed the services of an expert from Massey University for
providing training and technical assistance related to the use
of conservation tillage technology in wheat farming. This
helped launching a campaign for promotion of "Participatory
Resource Conservation Technology for Wheat Production" through
introduction of conservation tillage technology in rice
Training of trainers, field
staff, and farmers in conservation tillage technology.
Assistance of local
manufacturers for up-gradation of available zero tillage
Liaison with researchers,
policy makers, and implementation agencies for wide
spread promotion of technology.
Field demonstration on about
1000 acres, located at 150 sites for conservation
tillage wheat sowing in rice growing areas during Rabi
Training of Trainers, field staff, farmers, and field
demonstrations were conducted by the New Zealand expert in
Lahore, Gujranwala, Sialkot, and Hafizabad areas. A concluding
seminar on "Promotion of Participatory Resource Conservation
Technology for Wheat Production in Rice Cultivated Areas in
Pakistan" was held at Lahore. A number of recommendations were
made for further promotion of the technology on large scale.
Sowing with RCT during Rabi 1997-98
Wheat sowing season in 1997-98 was an unexpected abnormal wet
year with unprecedented rains in November and December. The
wet spell further continued through the Rabi season, which
affected even growth of the crop in low-lying areas. This
delayed normal cultivation even in non-rice
areas. The inability of farmers to cultivate and prepare seed
bed in conventional planting during this season was worked out
to be rather a blessing for farmers who wished to ow wheat
under zero tillage technology.
M/S Halcrow Rural Management conducted the impact assessment
of RCT technology during Rabi 1997-98 and found that:
mean wheat yield increased
by 148 kg/ha over conventional method of cultivation.
CT technology can lead to an
increase in stem borer larvae population in some areas,
but this increase is relatively insignificant compared
with the increase in population numbers when rice
stubble is left in fallow fields.
The time of planting of rice
has a significant affect on the incidence of stem borer
attack with late planted rice generally being
Rice stem borers are,
however, very easy to control using recommended
insecticides at the correct time.
The results of analysis supported the results reported by
Inayat et al. where they have stated that the rate of
mortality of hibernating stem borers was approximately the
same for RCT technology and control plots.
It is concluded that worries in some circles about problem of
increasing rice borer population associated with adoption of
RCT technology are unfounded.
Although the mean weed population density in the RCT
technology fields (22.6/m2) was 22.6 percent less than the
control plots (29.2/m2), which was not statistically
There were also no significant differences in mean height of
Sowing with RCT Technology during Rabi 1998-99
Keeping in view the positive impact of RCT technology on wheat
yield during Rabi 1997-98, the Directorate of OFWM, Punjab
continued demonstration of the same in the paddy country. CT
technology was demonstrated on 304 sites in the districts of
Mandi Bahawaldin, Gujrat, Sialkot, Gujranwala, Sheikhupura and
There were still certain
apprehensions among some researchers and experts about the
advantages, disadvantages and constraints of CT technology. It
was, therefore, felt to monitor and evaluate this technology
closely and vigorously before its wider replication in the
country. Accordingly, on the request of Director General
Agriculture (Water Management), an Expert Committee was
constituted by the Secretary Agriculture, Government of the
Punjab. The committee is comprised of experts from National
Agriculture Research Council (NARC), Pakistan Agriculture
Research Council (PARC), Ayub Agriculture Research Institute.
Faisalabad, Agriculture Extension and Adaptive Research wing
of the Punjab Agriculture Department, On-Farm Water Management
(OFWM) and a Professor (Retd.) from the Agronomy Department,
University of Agriculture, Faisalabad. The main task of the
committee was to:
* Monitor and evaluate the possibility of sprouting rice
stubble and stem borer attack on the subsequent crop.
* Ascertain the suitability of conservation tillage technology
before wider replication during the next year, i.e. 1999-2000.
* Recommend necessary steps to avoid any implementation
In addition, for independent organizations to closely monitor
and evaluate CT demonstration trials, International Irrigation
Management Institute (IIMI)-Pakistan on the request of
Director General Agriculture (Water Management) provided the
necessary research backup not only in rice-wheat cropping
system but also in cotton-wheat based systems in the Punjab.
Impact assessment of CT technology was, according, conducted
by the IIMI-Pakistan during Rabi 1998-99 and it was observed
that CT technology:
* Saves cultivation costs to the tune of Rs.500-800 per acre
in the case of small farmers and Rs. 1.000-1,500 per acre in
the case of medium to large farmers.
* Assists early sowing of the wheat crop.
* Saves 30-50 percent irrigation water in the case of first
irrigation after sowing. and 15-20 percent in subsequent
* Reduces weed germination up to a certain extent.
* Improves soil fertility.
* Enhances water and fertilizer use efficiency.
* Accelerates decay process of rice stubble, which improves
soil microbial activities.
* Increases wheat productivity in the range of 15-20 percent,
if property implemented.
Assessment of RCT during Rabi 1998-99
Because of the apparent
advantages of RCT during 1997, OFWM Punjab decided to
demonstrate this technique in the rice-wheat zone on large
number of farmers' fields in Rabi 1998. Field demonstration of
RCT was, accordingly, carried out at 304 different sites
covering 2,193 acres in the districts of Lahore, Sheikhupura,
Gujranwala, Sialkot, Gujrat and Mandi Bahaudin.
The major constraints faced during last year was that of
availability of limited number of RCT drills, i.e. only 5
drills were available with OFWM. At that time 5 drills were
borrowed from PARC. During Rabi 1998, 23 RCT were available
(12 from OFWM. 3 from FAO assisted "Special Program for Food
Security" and 8 purchased by the farmers). It is worth
mentioning that farming community appreciated RCT and
purchased 8 RCT drills to replicate this technology in their
Prior to sowing the wheat, training sessions were organized
for the OFWM staff and the farmers. During the sessions, the
problems of low wheat yield, particularly late planting after
rice crop and the possible benefits of using RCT were
highlighted. The operation of the zero tillage drill, in
particular calibration for different seed and fertilizer
application rates and actual operation in field were
demonstrated to the staff and farmers. Moreover, brochures on
zero tillage wheat production were prepared in English and
Urdu by OFWM. These were distributed to the field staff.
administrators, policy makers and farmers. In addition,
farmers' day was held at a number of locations, where farmers
could meet and examine the field days.
Prior to carry out impact assessment survey, OFWM field staff
was trained in field sampling techniques and identification of
stem borer larvae, weeds etc. Classroom lectures and field
practice were held in Lahore. Gujranwala and Gujrat.
OFWM staff conducted day to day supervision and collected data
regularly. During field visits, farmer's interviews and
personal observations were made as well regarding sowing,
machinery application, seed germination, stubble sprouting,
the presence of stem borer larvae etc. Detailed data on all
304 sites have been collected and is being analyzed. Due to
time constraint, a preliminary report on impact assessment of
RCT is prepared by taking randomly 5 sites per tehsil.
Accordingly, data of 65 sites
in tehsils of Daska, Phalia, Kamoke, Gujranwala, Nosheran
Virkan, Wazirabad,Gujrat, Hafizabad, Kharian, Mandi Bahudin,
Ferozewala, Lahore and Sheikhupura were taken for analysis.
Farmer-wise details regarding wheat yield data, net income
of stem borer larvae, and water saving are given in
annexures-C,D,E and F, respectively.
Number of stem borer larvae in the rice stubble was counted in
5 samples per acre of 1m2. To achieve this stubble had to be
dissected. Similarly, to monitor weeds, 5 samples per acre of
1m2 were taken. Crop cutting were used to compare yields from
RCT and control plots. In each plot, 4 crop cuttings were
taken at random each measuring 2m x 2m (4 m2). The weight of
wheat bundles was recorded and ears were removed and dried.
Later, the ears were thrashed and the grains were weighed.
The monitoring and evaluation of RCT field demonstration as
indicated above were carried out by making physical
measurements (where possible), interviewing farmers, and by
recording observations based on the following indicators for
both the RCT and conventional practices:
* Time savings in wheat sowing
* Costs involved in seedbed preparation
* Stem borer infestation
* Weed infestation
* Wheat yield
* Yield trend with time of sowing
* Net income
* Views on future prospects of adoption of RCT.
Results and Discussions
Results of the impact
assessment survey of RCT are given below:
(i) Time Saving in Wheat Sowing
On majority of the farms it was observed that RCT saves
wheat-sowing time by at least one week (4-11 days). This was
mainly due to the fact that this technique allowed wheat
sowing in the rice harvested fields having excessive soil
moisture. which would otherwise be not possible with
conventional method of seedbed preparation. The time saving
could even be better on larger farms.
(ii) Cultivation Cost
Under conventional cultivation plots, about 5-6 plowing and
same number of planking were performed to each proper seedbed
preparation. This costed on an average Rs.700 per acre
(Rs.350-Rs. 1,000) against average RCT cost of Rs.148 per acre
(Rs.100-Rs.150) - a saving of Rs.552 per acre. It clearly
indicates that RCT also saves expenditure involved in seedbed
preparations by eliminating plowing and planking costs.
(iii) Saving in Irrigation Water
Data on 18 plots applying tubewell water (only) was analyzed
and it was observed that there were saving of 21-63 percent
(on an average 38%) in irrigation water during the first
irrigation whereas, water savings during subsequent
irrigations were about 6-45 percent (on an average 25%).
Farmers appreciated RCT as it
allowed rapid movement of water to the other end of the field
as a result of less deep percolation. On the other hand with
conventional tillage method , more water is required to be
applied to completely irrigate a field. It can be inferred
that RCT not only increases water use efficiency but also
results in water saving.
(iv) Stem Borer Infestation
There was no significant difference between the number of
larvae in the RCT and control plots.
Farmers are mostly using
weedicide on paddy crop, and as a consequence, this might be
one of the reasons for very few cases of presence of stem
borer in the rice stubble. The time of planting of rice has a
significant affect on the incidence of stem borer attack with
late-planted rice generally being most susceptible. However,
rice stem borers are very easy to control by using recommended
insecticides at the correct time. The findings of OFWM staff
are, therefore, in agreement to the monitoring results of rice
stem borer conducted by M/S Halcrow Rural Management and
report of Inayatullah et al (1989).
(v) Weed Infestation
It was observed that weed growth per unit area was about 30
percent less in RCT plots (3.83/m2) as compared to plots with
5-6 plowings (5.3/m2). It was also observed that weeds in RCT
plots were much weaker than those in the control plots and
were easy to control by weedicide application.
An early decaying of rice stubble in RCT plots in contrast to
control plots was also observed. This was mainly due to the
fact the nitrogenous fertilizer has close contact with the
roots of rice stubble, which enhanced stubble rotting. This
phenomenon also results in increased soil microbial activities
thereby, improving soil fertility
(vi) Wheat Yield
It was observed that number of tillers per square meter on
RCT plots (383/m2) were 10 percent higher than those on the
control plots (346/m2). For all 65 sites, the mean yield of
wheat planted with RCT was significantly higher than the
control plots, i.e. 1,592 kg/acre (800-2320kg/acre) from RCT
compared with 1,361 kg/acre (461-1920kg/acre) from the control
plots - an increase of 231 kg/acre (17%). It can be easily
inferred that application of RCT provides better environment
for wheat growth by allowing early sowing of wheat, better
water and fertilizer uptake etc.
(vii) Yield Trend with Time of Planting
The wheat sowing date of RCT and Control plots were almost
the same. The spread of planting time was from 26th October to
12th December. The affect of planting date on yields in case
of RCT plots is shown in Fig.3 and 4, respectively. Fig-3
gives overall picture of wheat sown in the season whereas,
Fig-4 indicates the loss in wheat yield planted after 20th
November. The mean yield on RCT plot falls by about 1.4 kg per
day (Fig-3). The decrease in yield after 20th November was
much larger i.e. 13 kg per day (Fig-4) on the RCT plot (0.8%
Similarly, the affect of
planting date on yields in case of Control plots is shown in
Fig.5 and 6, respectively. Fig-5 gives overall picture of
wheat sown in the season whereas, Fig-6 indicates the loss in
wheat yield planted after 20th November. The mean yield on
Control plot falls by 1.35kg per day (Fig-5). The decrease in
yield after 20th November was much larger i.e. 7.4kg per
day (Fig-6) on the control plot (0.5% per day).