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Abstract Two field experiments were carried out at Nubaria Experiment Station, Agricultural Research center, to study biological and economical efficiencies of some combinations of two intercropping systems, i.e., maize/soybean and maize/sunflower in 1991 and 1992 seasons under calcareous soil conditions. Cultivars used of the Intercrops were maize, three way cross, Giza 310, f soybean cv. Crawford and sunflower cv. Pioneer hybrid No. 1. Intercropping treatments were two rows of maize alternated With four rows of soybean (or sunflower), (2:4), alternative pair of rows (2:2) and alternative triplet of rows (3:3). The intercropping patterns were checked against sole cropped maize and saoybean in the first system and maize and sunflower in the second system. plant densities of the check plants were 24, 120 and 24 thousand plants of maize, soybean and sunflower, respectively. Maize or sunflower were seeded simultaneously in ’hills, 25 cm. apart on one side of the ridges, whereas, soybean was seeded three days after irrigation in hills, 20 cm apart on both sides of the ridges. Thinning was carried out leaVing one plant/hill for both maize and sunflower, but leaving two plants/hill in case of soybean. 128 All treatments of both experiments were assigned in complete randomized block design in four replications. Results obtained could be summarized as follows: FIRST EXPERIMENT INTERCROPPING MAIZE WITH SOYBEAN A) Maize growth, yield components and yield: 1- Plant height of maize was not significantly influenced by intercropping pattern. Nevertheless, no any maize plants in the intercrop combination studied did catch up in height with sole cropped maize. 2- Ear height on maize plants was not also influenced by inter cropping. Nevertheless,ear height In alternate pairs of rows was ever the farthest from the grounnd. There was also no relevance between the topmost ear leaf area and the intercroppinq system. 3- The effect of intercropping on the average number of leaves per plant was not significant. The trend was also not regular. 129 4- Ear length as well as ear diameter of maize grown in the alternative row pattern (2:4) ranked first or second, whereas, ear length and ear diameter of maize plants grown in equal alternative pair of rows with soybean ranked first in 1992, but were the second in 1991 season. 5- Maize plants in 2:4 pattern had the highest number of grains/row. The equal alternative row patterns (3:3) and (2:2) ranked the second and the third, respectively, within the intercrop combinations. Pure stand plants exceeded the latter two patterns in this trait. 6- Maize plants in (2:4) pattern beared more ears on the stalk than other intercrop combinations. On other hand, values equalized with those recorded on those grown solid. 7- Maize plants in (2:4) pattern had the heaviest ear weight when compared with other intercrop combinations. Differences with other intercrop combinations were significant. On other hand, equal alternative rows poattern (2:2)had the least values. Neverthless none of the intercrop combinations had an average ear weight heavier than the sole cropped maize. 8- Pattern (2:4) had the highest values of both seed index as well as shelling percentage over all other cropping systems in both seasons, although differences were not significant in most cases. 9- ”Actual” yield of maize plants grown alone was ever more than that obtained from other intercropping treatments. Pattern (2:4) produced the lowest yield/fad., whereas, the equal alternative rows (2:2) and (3:3) ranked the second and the third, respectively. Differences in yield between the pure stand maize and the intercrop treatments were significant. Significant differences in yield were also apparent between maize grown in the equal alternative row patterns (2:2), (3:3) and the alternative row pattern (2:4). 10- The ”adjusted” yields of maize in the intercrop combinations were higher than yield of maize grown in pure stand. The results also indicated that maize grown in the equal alternative row paatterns (2:2) and (3:3) outyielded that obtained from the (2:4) pattern. B) soybean growth, yield components and yield/fad 1- The tallest soybean plants we%e associated with the equal alternative pair of roWS. solid plants ranked the second, whereas, (3:3) and (2:4) patte%ns %anked the third and the fourth, respectivelY· 2- soybean plants in the alternative patte%n (2:4) had more branches/ plant. sole cropped soybean ranked the second, whereas, the equal alternative row patterns (2:2) and (3:31 occupied the third and the fourth ranks 1n both seasons. Significancy was observed among all treatments in the first season and between (3:3) and solid planting in the second one. 3- soybean plants qrown in pure stand had the hlqhest average number of pods/plant, whereas, those oriented in (2:4) pattern ranked the second (Only in 1992 season). But equal alternative row (2:2) and (3:3) patterns ranked the third and the fourth, respectively. Differences among all t%eatments were significant in the fi%st season. 4- The effect of intercropping patterns on seed index of soybean behaved similarly as recorded with other t%aits. Highest values were obtained when soybean oriented in the equal alternative row patterns and (2: 2 ) occupied the third and the fourth respectively. 132 (3:3) rank, 5- The ”actual” yield of soybean gro~ alone significantly exceeded yields of soybean in all intercrop combinations under study. The data also indicated that soybean in (2:4) pattern outyielded that of both equal pairs or triplet alternative row patterns. 6- The ”adjusted” yield of the intercropped soybean within any intercropping pattern was superior to that obtained from the sole cropped soybean. The increase has been diminished between soybean grown in (2:2) pattern and soybean grown in pure stand. C) competitive relationshiPs and yield advantages 1- Relative yiel (RY) values of maize or soybean were proportionall parallel with their areas gro~ in the intercrop associations. RY values of maize were higher than expected in all the intercrop combinations. 2- Results of land equivalent ratios indicated that all Intercrop combinations gave more yield advantage as compared with sole cropped maize or soybean. All LERs values obtained exceeded the unit in both seasons. The data also indicated that arranging both components in mixture of equal alternative patterns, i.e., (2:2) or (3:3) gave yield advantage more than (2:4) pattern. 3- Results of the relative crowding coefficient indicated that all K values, i.e., Km and KS gave yield advantage more than expected in any of the Intercrop combinations in both seasons. The results also revealed that all Km values within these patterns were relatively higher than those calculated for soybean plants. Results also indicated that Km and Ks values were positively correlated with the proportion of both components 1n the intercropplng systems. The more the crop grown area in the mixture was, the higher K value was obtained. 4- Aggressivity data indicated that the treatments effect of both the equal alternative row arrangement had relatively higher mutual competitive pressure on both crops than in (2:4) pattern. The results also 134 indicated that maize was always the dominant component, whereas, soybean was the dominated component in all intercropping combinations. 5- Results showed that maize was always more competitive than soybean in most of the intercrop combinations in both seasons. All eRs values of maize exceeded the unit, except, in 1992 season when maize was alternated with soybean in (2:4) ratio. eRs values of soybean were always lower than the unit, except, when soybean proportion was increased to its maximum in (2:4) pattern in 1992. The results also revealed that maize component had more competitive ability than soybean, except in case of (2:4) pattern where soybean had greater area in the mixture. D) Economic evaluation : 1- Results indicated that (2:2) pattern produced maximum Cereal Units from maize component, whereas, the least was obtained from (2:4) pattern. Cereal Units produced from soybean in (2:4) were highest, whereas, those obtained from (2:2) pattern were the least. Cereal Units produced from sole cropped 135 plants of either component were superior to all those obtained from either component in any intercroppin9 pattern. cereal units of total ”actual” yield produced from (2:2) patteln wele relativelY the highest, whereas, (2:4) pattern produced the least. Differences between both equal alternative roWS patterns were very minute. cereal units from sale cropped maize were always more than those obtained from any intercropping pattern, but all exceeded the sole cropped soybean. 2- The net return calculated from (2:2) and (3:3) patterns were evidently higher than that calculated from (2:4) pattern. pattern (2:2) had higher net return than (3:3) pattern. On other hand, the net return gained from each intercropping patterns exceeded that obtained from pure stand soybean. The monetary advantage behaved the same course of change as the net return. The data alsO revealed that the more the increase of LER value was, the more monetary advantage obtained. |