This document discusses a study on the growth and yield of agricultural crops intercropped under three multipurpose tree species in Mizoram, Northeast India. Key findings include: 1) Tree and crop growth was significantly higher in intercropping plots compared to sole cropping plots, with the highest growth seen under Melia azadirach and Gmelina arborea trees. 2) Soil fertility indicators like pH, organic carbon, and NPK levels were highest in maize intercropping plots, indicating tree-crop interactions enriched soil nutrients. 3) Crop yields of ginger, turmeric, and maize were maximized under Alnus nepalensis, followed by Melia

1. P.C. Vanlalhluna1 , U.K. Sahoo2 and S. L. Singh2
1Department of Botany, Pachhunga University College (A constituent College of
Mizoram University) Aizawl, Mizoram-796001, India
2Department of Forestry, School of Earth Sciences and Natural Resource Management,
Mizoram University, Aizawl-796 004, India
Growth and yield of agricultural crops
intercropped under three multipurpose
trees (MPTs) in Mizoram, North-East India

2. INTRODUCTION
→ Mizoram is geographically located between
21˚58' to 24˚35' N latitude and 92˚15' to
93˚29' E longitude.
•Geographycally the state occupies an area of
21081 sq. kms.
•Nearly 6000 sq. kms of the area is under jhum
land uses, reckoning to 28.46% of the total
geographical area.
•The state of Mizoram shares many of the
attributes of mountainous regions elsewhere,
such as a high degree of remoteness,
inaccessibility, fragility, steep slopes, high
biodiversity and a large number of impoverished
people.

3. • The climate is humid subtropical characterized
by high rainfall.
• Most of the precipitation (over 80%) occurs
during May to September.
• The slope/gradient limit the cropping pattern
in the state.
• Nearly 80% of the land is above 30% slope,
further a major chunk of the land is under steep
to very steep slope hills limiting these are not
suitable for agricultural crops.
• However, the hilly terrain favours the
agroforestry practices which could bring better
crop productivity and sustainable land use.

4. MATERIALS AND METHODS
Study area
- Mizoram University campus located at 15km
south-west of Aizawl, the capital city of
Mizoram
- 23°42' to 23°46' N latitude
92°38' to 92°42' E longitude
and 845 m asl.
Average rainfall - 2500 mm and about 80% of the rainfall
occurs between June to September.
Temperature - 20° to 30° C in summer and from 8°
to 18° C in winter.
Soil - sandy loam with 51.24% sand,
20.71% silt
28.04% clay

5. Treatment
Tree seedling - One year old Alnus nepalensis(23cm),
Melia azadirach(35cm)
Gmelina arborea(30cm) height and
0.46 cm, 0.49 cm and 1.25 cm collar
diameter respectively were planted
Spacing - at a uniform 2.5 x 2.5 m spacing
(plant to plant and row to row)
Design - Randomized Block Design (RBD)
Replication - (3) three replications.

6. Intercropped - Local varieties of ginger (Zingiber officinale)
turmeric (Curcuma longa)and maize (Zea mays)
Weeding - Three weeding were carried out.
first weeding (mid-June)
second (mid-August)
last (first week of October).
Chemical control measures - were not provided
Irrigation of any sort
Crop was raised - rainfed condition.

7. Data recording
Observation - on growth parameters were made on
the tree species at six month interval
using standard methods.
Crop productivity- October (maize)
November (ginger & turmeric).
Soil samples - 0-15 cm soil depth.
Soils - air dried, processed and analysed for pH,
organic carbon, available N, P and K
using standard methods.

8. Soil moisture percent = (Fresh weight – Dry weight) x
100/ fresh weight.
Biomass production =Dry weight of sample/fresh weight
of sample x Total fresh weight of plant.
Land equivalent ratio (LER) = Ci/Cs + Ti/Ts.
where, Ci = crop yield under intercropping,
Cs = crop yield under sole cropping,
Ti = tree yield under intercropping,
Ts = tree yield under sole system.

9. RESULTS AND DISCUSSION

10. Species Growth after 3-year Green biomass productivity (kg/tree)
Height
(cm)
Girth/Collar
diameter(cm
)
Canopy
(m)
Litter fall
(t/ha)
Leaf Twigs Branch
Alnus nepalensis
Control 86.13±1.10 3.86±0.23 8.76±2.09 4.4±0.21 4.3±0.52 14.3±0.91 21.2±0.74
Ginger 106.46±0.17 3.91±0.21 10.85±2.02 4.6±0.23 4.5±0.41 15.2±0.52 23.3±0.23
Turmeric 110.93±0.67 3.95±0.20 10.95±3.05 4.7±0.74 4.6±0.85 16.1±0.32 24.4±0.21
Maize 128.73±1.35 4.00±0.08 11.06±3.11 4.7±0.11 4.6±0.21 16.3±0.50 25.3±0.23
CD (P<0.05) 4.41 0.03 0.03 0.05 0.02 0.06 0.09
Melia azedarach
Control 339.06±1.34 9.40±0.08 6.8.15±1.19 3.2±0.55 4.0±0.22 12.7±0.33 18.5±0.11
Ginger 356.53±1.73 9.54±0.11 7.9.56±2.12 3.5±0.25 4.3±0.62 14.3±0.41 19.0±0.14
Turmeric 362.26±3.17 9.62±0.20 7.9.66±3.15 3.6±0.71 4.4±0.41 15.5±0.47 20.2±0.05
Maize 380.33±0.29 9.74±0.15 8.03±2.13 3.7±0.21 4.5±0.33 16.6±0.03 21.2±0.07
CD (P<0.05) 4.62 0.09 0.01 0.01 0.01 0.09 0.07
Gmelina arborea
Control 342.33±1.61 9.30±0.04 13.10±2.09 5.6±0.88 4.6±0.52 17.6±0.04 31.1±0.41
Ginger 354.06±1.57 9.44±0.10 15.52±2.02 5.9±0.62 4.9±0.24 18.2±0.56 32.2±0.63
Turmeric 359.33±1.07 9.52±0.15 15.62±1.25 6.0±0.29 4.8±0.01 19.0±0.04 33.0±0.25
Maize 376.13±1.24 9.61±0.13 16.00±1.15 6.2±0.47 4.9±0.55 19.5±0.05 34.5±0.52
CD (P<0.05) 4.58 0.06 0.08 0.08 0.05 0.04 0.03
Table 1. Growth and productivity of the tree species over a 3-year period.

11. Growth of plants and biomass productivity
The growth differences were significant (P< 0.05)
between the treatments.
The maximum height and collar diameter were
attained by Melia azadirach intercrop plot (380.33 &
9.74 cm) > Gmelina arborea (376.13 & 249.61 cm) >
Alnus nepalensis (128.73 & 4.00 cm).

12. It was observed that the tree height and collar
diameter were always higher in the intercropped plots
than that of the sole crops.
The canopy cover, litter fall and green biomass
productivity were maximum in Gmelina arborea
intercroped > Melia azadirach > Alnus nepalensis.
The plants under intercropped plots were always
taller, thicker and have greater green biomass
productivity. This may be due to their ability to
retained more soil moisture and provided better
microclimatic favouring growth performance

13. Species pH Organic
carbon (g/kg)
Available nutrients
N (%) P (kg/ha) K (kg/ha)
Alnus nepalensis
Control 4.8±0.21 5.2±0.45 0.52±0.03 25.08±0.02 149.22±0.02
Ginger 5.0±0.36 5.3±0.36 0.74±0.01 25.09±0.03 156.54±0.55
Turmeric 5.1±0.05 5.4±0.21 0.73±0.01 26.78±0.05 156.55±0.49
Maize 5.2±0.12 5.6±0.33 0.74±0.02 25.05±0.02 157.53±0.47
CD (P<0.05) 0.06 0.92 0.02 0.03 0.73
Melia azedarach
Control 4.8±0.05 5.0±0.85 0.50±0.02 21.02±0.03 148.03±0.01
Ginger 4.9±0.85 5.3±0.96 0.74±0.01 22.03±0.07 156.34±0.35
Turmeric 5.0±0.23 5.5±0.56 0.73±0.01 23.04±0.31 156.57±0.49
Maize 5.1±0.25 5.6±0.41 0.74±0.02 22.01±0.03 157.24±0.40
CD (P<0.05) 0.04 1.02 0.03 0.02 0.72
Gmelina arborea
Control 5.0±0.24 5.4±0.27 0.51±0.11 33.01±0.05 148.08±0.04
Ginger 5.1±0.01 5.6±0.09 0.73±0.01 34.02±0.02 155.34±0.51
Turmeric 5.2±0.32 5.6±0.25 0.73±0.01 35.04±0.01 156.54±0.50
Maize 5.3±0.56 5.9±0.05 0.72±0.03 33.01±0.03 156.52±0.56
CD (P<0.05) 0.03 0.09 0.03 0.02 0.73
Table 2. Effect of tree cover on physico-chemical properties of soils over a 3-year period

14. Fertility status of the soil
The soil pH and organic carbon show a significant
(P<0.05) variation between the treatments.
Similarly, the NPK content in the soil also varied
significantly (P<0.05) between the treatment.
The NPK level in general was maximum under tree-crop
interaction than in sole crop (control). More litter
production and subsequent litter decomposition might
have enriched soil with more nutrients level.
The order of the nutrient level in the field was maximum
in maize > turmeric > ginger respectively.

15. Species Rhizome/ Grain yield
(t.ha-1)
Density
(ha-1)
AGB
(g/plant)
Alnus nepalensis
Control 5.11±0.02 33,597.23±0.53 12.76±2.09
Ginger 6.22±0.08 45,619.53±0.05 13.85±2.02
Turmeric 5.64±0.01 42,523.05±0.21 14.25±3.05
Maize 7.07±0.02 47,295.85±0.85 15.06±3.11
CD (P<0.05) 0.42 - 0.58
Melia azedarach
Control 5.01±0.04 33,450.52±0.23 12.92±0.05
Ginger 6.20±0.13 45,512.62±0.12 15.57±2.12
Turmeric 5.62±0.05 42,510.32±0.52 15.66±3.15
Maize 6.52±0.02 47,150.06±0.41 16.00±2.13
CD (P<0.05) 0.35 - 0.42
Gmelina arborea
Control 6.01±0.03 36,253.03±0.52 13.51±0.04
Ginger 6.18±0.06 45,850.85±0.23 15.52±2.02
Turmeric 5.60±0.02 42,486.69±0.51 15.62±1.25
Maize 6.21±0.05 45,986.32±0.45 16.03±1.15
CD (P<0.05) 0.08 - 0.51
Table 3. Yield of intercrops under different tree species over a 3-year period.

16. Crop yield
The yield of crops differed significantly (P<0.05)
between the treatments and was influenced by tree
association.
Ginger (6.22 t.ha-1), turmeric (5.64 t.ha-1) and maize
(7.07 t.ha-1) registered maximum yield under Alnus
nepalensis > Melia azadirach > Gmelina arborea.
Maximum crop yield under Alnus nepalensis may be
due to their ability to fix atmospheric nitrogen through
symbiotic and non-symbiotic association conditions.
In general, the crop yield was found better under
intercropped than control. This may be due more litter
production and subsequent litter decomposition under
trees favouring higher soil moisture and nutrients
retention contributed to higher crop yield

19. Parameters Ginger Turmeric Maize
Number of finger/cob
Control 5.93±0.02 5.73±0.01 7.22±0.02
Alnus nepalensis 6.70±0.01 6.58±0.02 7.01±0.01
Melia azedarach 6.60±0.03 6.47±0.01 6.99±0.03
Gmelina arborea 6.49±0.04 6.33±0.03 5.72±0.01
CD (P<0.05) 0.88 0.84 0.64
Finger size/length of cob (cm)
Control 6.80x5.71 4.59x4.13 16.92±0.03
Alnus nepalensis 8.27x7.99 6.65x6.31 16.71±0.02
Melia azedarach 8.22x7.91 6.52x6.26 16.34±0.02
Gmelina arborea 8.21x7.83 6.35x6.20 16.31±0.01
CD (P<0.05) - - -
Table 4. Intercrop growth under different tree species (after 3-year)

20. Crop productivity
Crop growth differed significantly (P<0.05) between
the treatments.
Better finger size and higher finger number were
recorded in Alnus nepalensis > Melia azadiranch>
Gmelina arborea.
Better finger size and higher finger number under
Alnus nepalensis may be due to their ability to fixed
atmospheric nitrogen through symbiotic and non-
symbiotic association condition.
It was also observed that better finger size and higher
number of finger were observed in tree-crop
intercropped plot than control. This may be due to
higher quantities of leaf fall and decay of root biomass
in intercropped plots than sole crops.

21. Species Land Equivalent Ratio
Crop Tree Total
Alnus nepalensis
Ginger 1.21 1.10 2.31
Turmeric 1.10 1.13 2.23
Maize 1.38 1.16 2.54
Melia azedarach
Ginger 1.23 1.06 2.29
Turmeric 1.11 1.13 2.24
Maize 1.30 1.20 2.50
Gmelia arborea
Ginger 1.02 1.03 2.05
Turmeric 0.93 1.06 1.99
Maize 1.03 1.10 2.13
Table 5. Land Equivalent Ratio of different agroforestry systems in Mizoram.

22. Land equivalent ratio
It was observed that land equivalent ratio was found
to be more than unity (1) in all the treated plot. This
showed that there is advantages in tree-crop
interaction.
Land equivalent ratio (LER) was found maximum in
Alnus nepalensis(2.54) intercroped plot > Melia
azidarach(2.50) > Gmelina arborea(2.13).

23. Studies on tree-crop interaction are very vital for
prescribing suitable agroforestry models in hilly region
like Mizoram where there is an urgent need for finding
suitable farming practices alternative to shifting
cultivation (jhum).
The present findings suggest that introduction of
multipurpose trees along with agricultural crops could
bring a change to the prevaling widely practiced old-age
traditional Jhum and may result in better crop yield and
sustainable land use.
CONCLUSIONS

24. THANK YOU