Effect Of A Polymer On Growth And Yield Of Soybeans (Glycine Max) Grown In A Coarse Textured Soil

Abstract

The water holding capacity of coarse textured soils is low. It can be increased by the addition of soil conditioners such as the cross-linked polymers (PAM). A synthetic anionic acrylic copolymer (ALCOSORB400) was mixed with a sandy soil at 5 different rates (0, 0.05, 0.1, 0.2 and 0.3% PAM by weight) and subjected to 5 different irrigation regimes (3, 4, 5, 6 and 7 days interval between 2 irrigations). Soybean (Glycine max; CV Stephens) was grown during the period from January to March 2001 in pots containing 800 g of treated soil under glasshouse environment. Dry matter productions at 20, 40 and 60 days after planting (DAP), plant height at maturity and grain yield at harvest were determined. The results indicated that the amount of dry matter productions at 20, 40 and 60 DAP were found to be higher with increasing amounts of PAM in soil and decreasing intervals between 2 consecutive irrigations. Similar relationships were found for plant height at maturity. Soybeans grown in soils treated with 0.05, 0.1 and 0.2% PAM achieved grain productions which were about 6, 9 and 14 times greater, respectively, than that in control soil under 3 days of irrigation interval. It was also found that 0.05% PAM in soil with 4 days irrigation interval and 0.1% PAM in soil with 5 days irrigation interval enabled plants to achieve grain yields higher than that of control soil with 3 days irrigation interval. Therefore, crops in coarse textured soils treated with polymers can produce more grain or dry matter yield often under low frequent irrigations. It can also help to save water, time, money and energy which otherwise spent on high frequency irrigations. These findings also have potential beneficial implications to growing garden plants, pot plants, glasshouse plants and/or general horticulture.