Integrated nitrogen management in increasing yield and economic profitability of broccoli (Brassica oleracea var. italica L.)

The experiment was conducted at Bangabandhu Sheikh Mujibur Rahman Agricultural University during the period of November 2014 to April 2015 with a view to assess the combined effect of inorganic and organic sources of nitrogen on yield of broccoli and to develop a combined dose under integrated plant nutrition system (IPNS) for broccoli production. Four levels of Nitrogen (N) as 140, 160 and 180 kg N ha-1 as urea super granules (USG) and 180 kg N ha-1 as prilled urea (PU) as well as three different organic nitrogen sources (IPNS based) were considered to comprise 24 treatments combinations. The experiment was laid out in a randomized complete block design with three replications. USG along with organic manures showed better yield performance regarding yield attributes and yield compared to PU. The highest head yield (14.7 t ha-1) was found in USG-N160 kg/ha+ Oil Cake (OC)2t/ha followed by USG-N180kg/ha+ OC2t/ha (14.5 t ha-1). The maximum lateral head yield (6.612 t ha-1), marginal rate of return (132), and benefit cost ratio (4.00) were recorded in USG-N160kg/ha+ Poultry manure (PM)3t/ha. The treatment PU-N180+PM3 also showed better performance regarding yield (13.7 t ha-1), harvest index (27.1%) and benefit cost ratio (BCR) (3.84). Therefore, USG @160 kg N ha-1 + 3 t ha-1 poultry manure as adjusted N126P22K62S14Zn2B1Mo0.8 kg/ ha+3 t/ha PM or PU @180 kg N/ ha + 3 t/ ha poultry manure as adjusted N146P22K62S14Zn2B1Mo0.8 ha+3 t/ ha PM can be recommended for broccoli production in Grey Terrace Soil

Long-term Application of Organic Residues to Improve Soil Properties and to Increase Crop Yield in Terrace Soil of Bangladesh

A field experiment was carried out from 1988 to 1993 at IPSA, Bangladesh, to evaluate the effects of long-term application of organic residues on the improvement of soil chemical and physical properties and on the increase in the crop yield. Five kinds of organic residues (no-application, rice straw, ipilipil leaves, compost, and cowdung) were applied every June to cover soil surface uniformly as a thin layer and incorporated into the soil to the depth of 10 cm. Rice (July to October) and wheat (mid-November or December to March) were cultivated in rotation under the combination of five organic-residue treatments and three levels of inorganic N fertilizer. The soil is terrace soil and was originally poor in chemical and physical properties. By application of organic residues, organic matter and total N contents of the surface layer were remarkably increased until nearly double. The soil increased in amount of available water by 50 %, became less compact and more porous, and increased in infiltration rate, although these improvements were limited to the ploughing depth of maximum 10 cm. Among the organic residues, compost made of rice-straw and cowdung was the most effective to improve both chemical and physical properties. Rice straw tended to improve physical properties rather than chemical properties, while ipilipil leaves and cowdung were effective to the improvement of chemical properties. Effect of application of organic residues on the increase in the crop yield was more distinct for rice than for wheat, because organic residues were applied just before transplantation of rice seedlings. Grain yield of rice increased with year and attained the maximum and stabilized state after 4th year from initiation of the experiment in which grain yield of more than 2.5 Mg/ha was obtained under no-application of inorganic N fertilizer. With a combination of 75-100 kg/ha of N fertilizer, yield over 4 Mg/ha was expected. Among the organic residues, compost was the most effective, closely followed by ipilipil leaves and cowdung. Grain yield of wheat increased linearly with amount of N fertilizer applied in each year. Maximum grain yield was 354.0 Mg/ha under 120 kg/ha of N. Application of organic residues significantly increased grain yield of wheat. But, accumulation effect of organic residues on the yield was not observed and grain yield was still below 1.0 Mg/ha under no-N application even after 5 years of cultivation. Among the organic residues, compost brought about the highest grain yield. Compost was concluded to be the most effective organic residue to improve soil chemical and physical properties under the crop rotation of rice and wheat in terrace soil. It was estimated for compost to increase the rice yield mostly through improvement of chemical properties and to contribute to increase in the wheat yield by improvement of physical properties

Preliminary Assessment of Quality of Water in Gazipur District, Bangladesh

Total 26 water samples were collected in BSMRAU campus and in Gazipur District where BSMRAU is situated, Bangladesh, in March （the late dry season） 2001. Samples were taken from surface water （river, pond, lake, canal and reservoir） and ground water. Ground water was found to be suitable to drinking or irrigation. Quality of surface water varied with sampling locations and water sources. Among surface-water samples, the concentration of NO_3^--N was highest for water taken from the Turag River （3.6 mg/L） followed by water from the Belai River （2.5mg/L）. The P concentration was also highest for water of the Turag River （0.34mg/L）. Discharge of municipal waste water from houses along the river, in addition to inflow of N fertilizer applied to agricultural fields, was proposed to the contamination of the Turag River. Progress of eutrophication or pollution in small rivers in Gazipur District may cause a serious impact on environment and human health in future. Detailed and comprehensive assessment is strongly requested