Gumphol Chaidox
Kasetsart University, Bangkok 10900
………………………….
Experiments on corn-legume intercropping were
conducted at Sri Samrong district, Sukhothai province during July 1989-March
1990. Treatments were arranged in
a split plot design in RCB with four replications. Main plots were 16-20-0 fertilizers at the rates of 0 (-F)
and 30 (+F) kg/rai (30 kg + 6 kg P2O5/rai). The
subplots were:
1) KUSX 2301 corn (C)
2) corn + lablab bean or legume (CLL) or corn intercropped with lablab bean
3) corn + lablab bean as green manure (CLLgm)
4) corn + lima bean (CLM)
5) corn + lima bean as green manure (CLMgm)
6) corn + black bean (CBB)
7) corn + black bean as green manure (CBBgm)
8) control + rice bean or no corn planting and
only rice bean was planted
(CRB) and
9) control + rice bean as green manure
(CRBgm).
The experiments were conducted in two sites (in
Chai Nat soil series and in Kampaeng Saen soil series) during the 1989 rainy
season. To evaluate the residual
effect of associated legumes on corn yield in the following dry season, KUSX
2301 corn was planted in the subplots in Chai Nat soil series, while in
Kamphaeng Saen soil series the same experiments were repeated as in the 1989
rainy season.
From the 1989 rainy season results, in Chai Nat
soil series, greater intercropped/associated-corn grain yields were obtained in
corn+rice bean as green manure (CRBgm), corn + lablab as green manure (CLLgm)
and corn+black bean as green manure (CBBgm) without fertilization (971, 939 and
922 kg/rai, respectively) as compared to planting corn alone with fertilization
at the rate of 30 kg/rai of 16-20-0 (839kg/rai). In Kamphaeng Saen soil series, the
intercropped/associated-corn with rice bean as green manure (CRBgm) and corn +
lablab as green manure (CLLgm) without fertilization (yielding 723 and 702
kg/rai, respectively) were promising, out-yielded planting corn alone (C) with
fertilization (654 kg/rai).
1989 rainy season results
Corn
grain yield (kg/rai) in
Treatment
Chai
Nat series
Kamphaeng Saen series
Under no
fertilization
2) corn +
lablab bean or legume (CLL)
- -
3) corn +
lablab bean as green manure (CLLgm) 939
723
4) corn
+lima bean (CLM)
-
-
5) corn
+lima bean as green manure (CLMgm) -
-
6)
corn+black bean (CBB)
-
-
7)
corn+black bean as green manure (CBBgm) 922
-
8)
control+rice bean or no corn planting (CRB) -
-
9)
control+rice bean as green manure (CRBgm)
971
702
Under
fertilization with 16-20-0 at 30 kg/rai
1) KUSX
2301 corn (C)
839 654
…………..
Remarks: - = no data
This trial has no unfertilized
check without green manure (intercrop), so it is impossible to say whether
there is a clear response to fertilizer or to the green manures.
For the dry season, residual effects of the
previous cropping systems were observed in Chai Nat soil series as corn planted
after the corn+black bean intercropping (CBB) and corn +lima bean intercropping
(CLM) without fertilization yielded (805 and 704 kg/rai, respectively) greater
than planting corn alone (C) with fertilization (688 kg/rai). In repeating intercropping in Kamphaeng
Saen soil series, corn+black bean as green manure (CBBgm) and corn + lablab as
green manure (CLLgm) without fertilization gave statistically different higher
grain yields (774 and 721 kg/rai, respectively) than planting corn alone (C)
with fertilization (688 kg/rai).
1989/1991 dry season results
Corn grain yield (kg/rai) in
Treatment
Chai
Nat series
Kamphaeng Saen series
(Only corn
was planted)
Under no
fertilization
2) corn +
lablab legume (CLL)
-
-
3) corn +
lablab as green manure (CLLgm) -
721
4) corn
+lima bean (CLM)
704
5) corn
+lima bean as green manure (CLMgm) -
-
6)
corn+black bean (CBB)
805
-
7) corn+black
bean as green manure (CBBgm)
-
774
8)
control+rice bean or no corn planting (CRB) -
-
9)
control+rice bean as green manure (CRBgm)
-
-
Under
fertilization with 16-20-0 at 30 kg/rai
1) KUSX
2301 corn (C)
with fertilizer
688
688
…………..
Remarks: - = no data
Nodule