Md. Moshiul Islam*
Department of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur P.O. Box 1706, Bangladesh;
Md. Razaul Karim
Department of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur P.O. Box 1706, Bangladesh;
Md. Moinul Hosain Oliver
Department of Agricultural Engineering, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur P.O. Box 1706, Bangladesh
Tahmina Akter Urmi
Department of Soil Science, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur P.O. Box 1706, Bangladesh
Md. Ashraf Hossain
Department of Soil Science, Bangladesh Agricultural Research Institute, Gazipur P.O. Box 1701, Bangladesh
M. Moynul Haque
Department of Agronomy, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur P.O. Box 1706, Bangladesh
Micronutrients; Lentil; Crop characteristics; Yield component; Seed quality; Soil properties
Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh
Crop-Soil-Water Management
Micronutrient, Lentil
2.1. Experimental Site and Soil The field experiment was conducted at the research field of the Pulses Research Sub-Station, Bangladesh Agricultural Research Institute (BARI), Gazipur, Bangladesh, during the winter season (November to February) of 2015–2016 and 2016–2017. The soil of the study area belongs to the chhiata series under the agroecological zone (AEZ) Madhupur Tract (AEZ-28). The experimental site has a subtropical humid monsoon climatic condition. It is characterized by comparatively high monsoon rainfall, high humidity, and high temperature, long days with less clear sunshine, and sometimes the sky remains cloudy for heavy rainfall during the period from April to September. Scanty rainfall, low humidity, low temperature, short days, and more clear sunshine characterize the period from October to March. The average temperature ranges from 15.0–36.1 ?C and average annual rainfall varies from 1500–2200 mm around the year. Initial soil samples (0–15 cm depth) were collected from different spots of the experimental field and the characteristics of the experimental soil are given in Table 1. 2.2. Experimental Design and Treatments The experiment was laid out in a randomized complete block design (RCBD) with eight treatments and three replications. The plot size was 4 m × 3 m. The treatments were T1 (Control), T2 (Zn2.0 kg ha−1 ), T3 (B1.5 kg ha−1 ), T4 (Mo1.0 kg ha−1 ), T5 (Zn2.0B1.5 kg ha−1 ), T6 (Zn2.0Mo1.0 kg ha−1 ), T7 (B1.5Mo1.0 kg ha−1 ), and T8 (Zn2.0B1.5Mo1.0 kg ha−1 ). Basal application of fertilizer was made with 15 kg nitrogen (N), 20 kg phosphorus (P), 30 kg potassium (K), and 10 kg sulfur (S) ha−1 in all plots. Fertilizers of each treatment were applied to their respective plots at the final land preparation. The sources of N, P, K, S, zinc (Zn), boron (B), and molybdenum (Mo) were urea, triple super phosphate (TSP), muriate of potash (MoP), gypsum, zinc sulfate, boric acid, and sodium molybdate, respectively. Disease-free vigorous lentil (BARI Masur-7) seeds were sown on 8 November 2015 and 2016 with the spacing of 30 cm × 5 cm. The seed rate was 30 kg ha−1 . Standard crop management practices were employed. No pests and diseases were observed during the experimental period. Crops were harvested at maturity. Data on yield contributing characters were recorded from 10 randomly selected plants from each plot. The seed yield (kg ha−1 ) was recorded by the whole plot technique. The seed yield was adjusted to 10% moisture level [18]. The adjusted seed yield at 10% moisture level per plot was converted to seed yield as kilogram per hectare. 2.3. Protein Percentage The protein percentage in lentil seed was calculated considering the pulses food factor 5.30 [19]. The protein content was measured by multiplying the % N content of seed with the pulses food factor 5.30 (% N × 5.30). 2.4. Chemical Analysis of Plant Samples The collected grain and straw were air-dried in ambient conditions and then oven-dried at 65–70 0C for 72 h. The dried samples were finely ground by using a Wiley-Mill with stainless contact points to pass through a 60-mesh sieve. Ground plant samples were digested with di-acid mixture (HNO3HClO4) (5:1) as described by Piper (1966) for phosphorus (P), potassium (K), sulfur (S), zinc (Zn), and boron (B). Total nitrogen was determined using Kjeldhal systems. Phosphorus was determined colorimetrically using the venadomolybdate blue ascorbic acid method by double beam spectrophotometry (Model no. 200-20, Hitachi, Tokyo, Japan). Potassium and zinc concentrations in the digest were directly measured by atomic absorption spectrophotometry (Model No.VARIAN SpectrAA 55B, Adelaide, Australia) and the sulfur concentration was determined by the turbidity method using BaCl2 by spectrophotometry. The boron concentration was also determined by spectrophotometry following the azomethine-H method. 2.5. Soil Analysis Soil samples were collected (up to 0–15 cm depth) at the initial stage and also after harvest from four different spots in each plot. The composite soil sample of each plot was brought to the laboratory for different soil analyses. Particle size analysis of the soil was conducted using the hydrometer method. The textural class was determined using Marshall’s Triangular Coordinates of the USDA system.
Agronomy 2018, 8, 100; www.mdpi.com/journal/agronomy
Journal