Macroalgae as Soil Conditioners or Growth Promoters of Pisum sativum (L)

Mexico has long littorals that receive great amounts of marine algae that are wasted despite being potentially useful as growth promoters without the inconveniences of agrochemicals. Some macroalgae have been used with excellent results as soil conditioners and fertilisers in agriculture. In this study nine macroalgae from the coasts of Veracruz (Gulf of Mexico) and one from Guerrero (Mexican Pacific), Mexico, were tested. They were added to the soil in the form of fragments and of silage in liquid around Pisum sativum plants. A two-way random design with four replicas was followed. Two controls, hormones and water, were also used. Growth was recorded every third day. Results showed that four algae promoted growth (p<0.05) Ulva fasciata (ensiling treatment) and Ulva lactuca (ensiling treatment) and Gracilaria caudata (fragment treatment) and Palisada perforata (fragment treatment), compared with the hormones and water controls. The activity of Ulva fasciata and Palisada perforata is recorded for the first time. Since the control plants treated with hormones grew much less than those treated with the four algae, we conclude that the release of all algae compounds was responsible for the growth, and not the hormone mimetics.