Effects of Ascophyllum Nodosum and Soil Amendments on the Development of Maize Seedlings Cultivated Under Acid Oxisol

Abstract

Introduction Maize (Zea mays L.) plays a fundamental role in Brazilian agriculture, and it is mostly cultivated in Brazilian Savannah areas, under high Al content and acidic pH. Aims The aim of this work was to evaluate the effects of soil amendments and A. nodosum extract on the initial development of the root system and nitrogen use efficiency of maize under aluminum toxicity. Methods The effects of lime and gypsum in combination with seed treatment + foliar application of Ascophyllum nodosum on shoot and root growth, plant nutrition and photosynthesis of 14-day-old maize seedlings were tested in two experiments. The experimental design was randomized 4x2 factorial, with the following treatments: lime (L), gypsum (G), lime + gypsum (LG) and control (C), cultivated with and without seed treatment and foliar application of the Ascophyllum nodosum. Results The treatments with A. nodosum extract led to an increase in the root area in the treatments with lime, and to a smaller transport of aluminum to the shoot of the plants. The lime and gypsum treatments were efficient in minimizing the deleterious effects of aluminum toxicity, even with their short-term application in sandy clay loam medium textured soil, providing better photochemical activity, better use efficiency of nutrients, better rooting and, consequently, higher dry weight of shoot and root. Conclusions The results show that the use of A. nodosum and soil amendments in acidic soils lead to promising physiological and morphological improvement, and by consequence, may influence in crop production.