Effect of organic and inorganic fertilizers on yield and quality of ruzi grass ( Brachiaria ruziziensis ) grown on saline sandy soils of the Northeast , Thailand

Most soils in the Northeast of Thailand are sandy in texture. They are poor both in physical and chemical properties. Saline soils currently occupy an area of approximately 17% of the region and are increasing annually. These saline sandy soil can be detrimental to plant growth and result in low yields, this being mainly due to low fertility, high soluble salts and low water holding capacity. To grow crops successfully, these soils must be improve. The objective of this study is to elucidate the effect of organic and inorganic fertilizers on yield and quality of ruzi (Brachiaria ruziziensis) grass on saline sandy soils of the Northeast Thailand. Experiment design was factorial in RCBD with 3 replications. Factors were 3 rates of chicken manure (0, 1.87 and 3.75 t/ha), 2 rates of rice husk (0 and 5 t/ha) and 3 rates of 15-15-15, inorganic fertilizer (0, 156 and 312 kg/ha). Ruzi grass seedlings were transplanted in to 2 × 3 m plot on a Typic Natraqualfs soil at a 30 × 30 cm spacing. Both fresh and dry weight of grass was measured at harvest. For dry weight, increasing rates of manure resulted in an increase in yield. These was significantly different between control and 3.75 t/ha. Rice husk also gave significant dry weight differences between control and 5 t/ha rate. For the 15-15-15, inorganic fertilizer, the application at 156 kg/ha increased dry weight significantly from control. There was a significant interaction between rice husk and inorganic fertilizer. It was concluded that chicken manure at 3.75 t/ha together with rice husk at 5 t/ha and fertilizer at 156 kg/ha was the best combination rate to give highest grass dry weight under this saline and sandy condition. Grass quality such as crude protein, neutral detergent fiber and acid detergent fiber were analysed. Soil chemical properties such as pH, EC, OM, total N, available P, exch, K and exch, Na were also analysed before and after the experiment. 1 Faculty of Agriculture, Khon Kaen University, Khon Kaen 40002, Thailand Introduction Most soils in the northeast are sandy in texture. They are poor in physical, chemical and biological properties. Saline soils currently occupy an area of approximately 17% of the region and are increasing annually. Most saline soils are also sandy, these saline sandy soils can be deleterious to plants and result in low yields, due to low fertility, high soluble salts especially sodium chloride, low water holding capacity and low cation exchange capacity. To grow crops successfully, these soils must be improve. The objective of this study is to elucidate the effect of organic and inorganic fertilizers on yield and quality of ruzi grass as well as the changes in soil properties used in the experiment. Materials and Methods Experiment design was factorial in RCBD with 3 replications. Factors were 3 rates of chicken manure (0, 1.87 and 3.75 t/ha), 2 rates of rice husk (0 and 5 t/ha) and 3 rates of 15-15-15, inorganic fertilizer (0, 156 and 312 kg/ha). Ruzi grass seedlings were transplanted into 2 × 3 m plot of Kula Ronghai series soil (Ki, Typic Natraqualfs) with 30 × 30 cm spacing. Both fresh weight and dry weight of grass were measured as well as grass quality. Soil properties before and after the experiment was also measured. Results and Discussion Some properties of Kula Ronghai series soil (Ki, fine-loamy, mixed, active, isohyperthermic, Typic Natraqualfs) before the experiment are shown in Table 1. This soil is slightly saline soil with high soil reaction (pH) low in plant nutrients but high in sodium and sandy in texture.