Integrated management of inputs to maximize crop yields in humid
highlands for food security
Sharma UC1, Sharma V2
1Centre for Natural Resources Management, V. P. O. Tarore, District Jammu - 181133
JandK, India ; [email protected]
2S.K. University of Agricultural Sciences and Technology, Chatha, Jammu - 180009
JandK, India
Keywords: nutrients, food deficit, shifting cultivation, cropping systems, north-eastern
region of India
Introduction
The crop production research has been reoriented as cropping systems research in the recent
years. Assessment of fertilizer schedule for a system is a complex problem because of so
many factors affecting availability of nutrients, their fixation and loss and residual affects
(Palaniappan, 1985). The cropping systems for an area must suit the local agro-climatic and
soil conditions and be superior in terms of their biological productivity with least disturbance
to ecosystem. The north-eastern region of India, with an area of 255,090 sq km, is
predominantly hilly. The population in the region has increased almost four folds between
1951(10.1 million) and 2001(39.3 million), within a span of 50 years, while food production
has not kept pace with this increase. The region has still a food grains deficit of about 2.1
million tonnes (Sharma, 1999). Shifting cultivation, the major land use system of the region,
is practised in 3869 km2 area, annually; however the total affected area is 14660 km2. It has
resulted in large scale deforestation, soil erosion and degradation of natural resources. The
practice was acceptable when shifting cycle used to be 25-30 years. Due to increase in
population at an annual compound growth rate of 2.43%, the shifting cycle has come down to
5-7 years. The practice results in annual loss of 88.3 and 0.218 million tonnes of soil and crop
nutrients, respectively, from the region. The region receives average annual rainfall of 2450
mm. The results reported in this paper are from a study undertaken to evaluate four potatobased cropping systems in terms of their productivity, nutrient uptake and recovery and,
economic return.
Materials and Methods
Field experiments were conducted for three consecutive years on a sandy loam soil (Typic
hapludalf) for integrated management of nutrients and water as ell as economics of four
potato-based cropping systems. The crop rotations were, potato–cauliflower, maize-potato,
rice-potato and potato-radish. The available N, P and K content of the experimental soil at
initial stage was 186, 6.8 and 201 kg ha-1, respectively, with pH 5.2 and EC 0.156 dS m-1.
The maize, rice and summer potato were the first crops in a sequence while cauliflower,
radish and spring potato were second crops. There were ten treatments as given in Table 1.
The treatments were replicated four times in a randomized block design. Full dose of P, K,
and FYM (farmyard manure) and half of N were applied at sowing time while rest half of N
was applied one month after sowing/planting of a crop. The FYM contained 0.40, 0.12 and
0.38 % of N, P and K, respectively, on fresh basis. The crop yields were recorded at harvest.
The benefit/cost or economics of a cropping sequence was calculated as per prevailing
market prices of different commodities. The soil and plant analysis was done as per
procedures underlined by Jackson (1973) and Piper (1950). The tillage practices were that the
potato, cauliflower and radish were grown by ridge and furrow methods, maize on flat beds
and rice as wetland cultivation.
Table 1. Fertilizer schedule for N, P, K (kg ha-1) and FYM (t ha-1)
Treat- Maize,
ments rice
N
F0
0
F1
50
F2
50
F3
50
F4
100
F5
100
F6
100
F7
150
F8
150
F9
150
summer potato
Cauliflower
spring
P
0
22
22
22
44
44
44
66
66
66
N
0
100
100
100
100
100
100
100
100
100
P
0
0
22
0
0
22
0
0
22
0
K
0
25
25
25
50
50
50
75
75
75
potato
,
K
0
0
42
0
0
42
0
0
42
0
radish
FYM
0
15
0
0
15
0
0
15
0
0
Results and Discussion
Crop yield
Summer potato responded significantly up to the application of 100, 44 and 50 kg ha-1 of N. P
and K, respectively. The application of FYM @ 15 t ha-1, however, enhanced the response of
the crop to 150, 66 and 75 kg ha-1 and highest tuber yield of potato was 23.23 and 22.31 t ha-1
in potato-cauliflower and potato-radish rotations, respectively. In the absence of P and K or
FYM, the curd formation in cauliflower was delayed and markedly small and loose curds
were formed. The application of P, K and FYM to cauliflower improved the ratio of curd to
foliage from 24.3% to 34.6%. Significantly highest grain yield of maize was obtained with
the F4 treatment and no further increase was found with higher level of applied nutrients
(Table 2). In maize-potato crop rotation, the tuber yield of potato increased by 11.0% with the
application of FYM and N over N applied alone. The increase in tuber yield may be
attributed to additional supply of nutrients through FYM as well as improved soil physical
condition for proper development of tubers. The residual effect of nutrients applied to potato
was observed on the subsequent maize crop during the second and third year of
experimentation. The response of rice to nutrients in rice-potato rotation was similar to
maize. Maximum significant yield of radish was obtained with the highest level of applied
nutrients that is 150, 66 and 75 kg ha-1 of N, P and K, respectively. The response of summer
potato, cauliflower and radish to nutrients at highest level of applied nutrients was due to the
reason that these crops are heavy feeders.
Nutrient uptake
Potato haulms (foliage) had higher concentration of N compared to tubers; however, in case
of cauliflower, curd had higher concentration of N than foliage. In maize, more N and
K concentration was found in stalks than grains while reverse was true for P concentration.
Highest uptake of N, P and K was found in potato-cauliflower rotation followed by potatoradish, rice-potato and maize-potato rotations, respectively (Table 3). Similar trend was found
in nutrient recovery also. In the nutrient balance sheet approach, it was found that N and P
had positive while K had negative balance in the soil. Removal of K was more than applied in
all the cropping systems except maize. The highest depletion of K was found in potato-
cauliflower rotation followed by potato-radish, rice-potato and maize-potato. The addition of
nutrients to soil for a particular crop would depend on loss due to leaching, volatilization,
fixation and residual effect of nutrients applied to the preceding crops. On an average, of the
total nutrients removed, summer potato accounted for 57.7% N, 53.4% P and 65.6% K while
spring potato removed only 41.9% N, 43.1% P and 47.0 % K.
Table 2. Mean (average of 3 years) yield of different crops (t ha-1)
Treat
-ment
F0
F1
F2
F3
F4
F5
F6
F7
F8
F9
CD,
p= 0.05
System
Summer
potato
7.80
16.81
15.65
14.71
20.66
19.72
18.41
23.23
21.75
20.31
1.59
I
Caulif
lower
1.12
8.90
3.25
0.99
9.51
4.02
1.63
10.24
5.80
2.04
1.26
System
Maize
0.68
1.21
1.06
0.95
1.75
1.50
1.43
1.71
1.68
1.55
0.19
II
Spring
potato
5.79
10.88
9.76
8.45
13.91
11.95
10.06
14.81
14.43
12.87
1.37
System
Rice
1.29
2.25
2.12
1.92
2.76
2.54
2.04
2.75
2.55
2. 23
0.31
III
Spring
potato
5.23
9.72
9.17
8.27
12.19
12.00
10.99
12.75
12.75
11.25
1.12
System
Summer
potato
6.15
14.75
13.66
12.25
18.23
18.06
16.23
22.31
21.05
19.02
1.69
IV
Radish
6.98
10.25
10.45
9.56
21.98
20.08
19.02
26.86
25.18
23.04
1.73
Table 3. Nutrient uptake, % recovery and benefit/cost ratio of different cropping systems
Cropping system
Potato-cauliflower
Maize-potato
Rice-potato
Potato-radish
Nutrient
N
185.1
129.2
163.1
172.4
uptake
P
17.6
9.5
14.6
15.7
K
175.8
122.0
149.9
159.5
%
N
89.0
58.7
74.3
85.6
recovery
P
20.2
15.4
17.4
18.2
K
140.6
113.2
125.5
132.4
Benefit/
cost ratio
1.79
1.36
1.59
1.76
Residual effect and economic return
Analysis of the soil samples after the completion of the experiments showed that there was a
build-up of nutrients in all the cropping systems over their initial status in the soil. The
available N and K content in potato-cauliflower system was significantly lower than other
systems while available P varied non-significantly. This may be due to more depletion of
these nutrients in this rotation. The beneficial effect of FYM on the available nutrient buildup in the soil was observed. Potato-cauliflower system was the most profitable followed by
potato-radish, rice-potato and maize-potato in that order. Maize proved to be non- profitable
mainly because of high precipitation and low summer temperature (15 to 27 OC), which
affected grain filling at maturity. Summer potato gave the highest net profit followed by
cauliflower, radish, rice and spring potato. The crop yields obtained in these four cropping
systems was 2.5 to 3.5 times higher than that of shifting cultivation.
Adopting these sustainable and eco-friendly cropping systems by the cultivators has ensured
enduring food security in the region. This would not only bridge the gap of food deficit but
make the region a food surplus zone. This will be possible only when a balanced use of inputs
is made to properly selected cropping sequences according to the local agro-climatic
situation.
References
Jackson, M. L. 1973. Soil Chemical Analysis. Prentice Hall of India, New Delhi.
Palaniappan, S. P. 1985. Cropping Systems in the Tropics – Principles and Management.
Wiley Eastern, New Delhi.
Piper, C. S. 1950. Soil and Plant Analysis. Inter Sci. Publ. Inc., New York.
Sharma, U C 1999.Food Security in the northeast : new paradigms. In : Persrpective for
Planning and Development in North Eastern India (ed. by R. C. Sundariyal, Uma
Shankar and T. C. Upreti), G.B. Pant Institute of Himalayan Environmental and
Development, Almorah, India, pp 197-212.