Abstract
The study was conducted to find out the effects of two management practices,
biomas.s incorporation (BI) and crop combination (CC) in an alley cropping system. The
main objective was to assess the soil nutrient status, soil loss through sheet erosion, yield
Of alley crops and finally financial benefit. A split-plot design in randomized complete
block design (RCBD) was followed with three replications. The three main plots (BI)
treatments were, BII (biomass upper 1/3rd portion Of alleyways), BII (biomass upper 2/3
portion of alleyways), and 1313 (biomass whole alleyways as control) were randomly
placed in the main plots. Three sub-plot (CC) treatments were CCI (pure stand corn as
control), CC2 (Corn+Sweet potato), and CCs (Corn+Peanut) were placed in the three sub-
plots. The study was carried out for two consecutive seasons (wet season, 1999 and dry
season, 1999-2000).
The results showed that soil pH became slightly acidic compared to its previous
value. The organic matter (0M) content after the wet season crop harvest was lower,
although more than 2.5 tons of green leaves (Fleminigia macrophylla) were incorporated
in the soil. The sharp increase of 0M Content was noticed after dry season crop harvest.
In most cases, the avail. P and exch. K decreased due to cropping. In general, CEC had a
slight increase due to the effect of BI and CC. The differences in between the up-slope
and down-slope of alley were significant for 0M, P, and K.
In the wet season, sheet erosion was not statistically significant but in the dry
season, erosion in the down-slope was statistically significant. In the dry season, the
maximum sheet erosion due to BI was recorded from the Bli (25.87 t ha-1) and the
minimum fronl the B12 ( 21.84 t ha-1). On the other hand, the maximum sheet erosion due
to CC was recorded from the CC3 (26.41 t ha-l) and the minimum from the CC2 (21.02 t
ha-l). Neither wet nor dry season, the interaction effect was not significant.
The grain yield and dry matter production of corn (wet and dry season), revealed
that 1312 gave the maximum corn grain yield (2.366 t ha-l) in wet season while the BIS
produced the highest corn grain yield (2.756 t ha-l) in dry season. The pure stand or sole
corn (CCD gave the highest yield in both season (2.442 and 2.707 t ha-1 in wet and dry
season respectively). The lowest corn grain yield (2.136 and 2.439 t ha•l in wet and dry
seasons respectively) were obtained from the CC2.
The highest marketable root yield of sweet potato (5.37 and 9.64 t ha•l in wet and
dry season respectively) was found from B13. It was also noticed that the marketable root
yield of sweet potato was higher in the dry season. The peanut yield was also affected by
BI, although it was not statistically significant. Treatment 1313 gave the highest nut yield
(0.647 t ha-l) in wet season and BII gave the highest (0.555 t ha-l) nut yield of in dry
season. In both seasons, the peanut yield was not satisfactory.
The financial performance of the tested treatments were analyzed and found that
the highest gross return (GR), and net return (NR) amounting to and 45,266 ha-l
respectively were flom the treatment combination B12*CC2 which was followed by the
treatment BII*CC2 (P62,866 and 43,386 ha-l respectively). In the wet season, the
benefit-cost ratio (BCR) of 3.33 was highest from the treatment combination B12*CC2. In
the dry season, the highest GR, and NR amounting toP82,770 and 62,075 ha-l
respectively were from the treatment combination B12*CC2 which was followed by the
treatment B13*CC2 (GR and NR amounting to P79,970 and 59,275 ha-l respectively). In
the dry season, the benefit-cost ratio (BCR) was highest from the treatment combination
B12*CC2 (4.00). The treatment B12*CC2 was identified as the best combination for
financial return in both the seasons