Optimization of dietary protein level for good aquaculture practice based carp fattening in ponds under drought prone area of Bangladesh

Good aquaculture practice (GAP) based carp fattening is a potential technique to obtain higher and safe fish production within shorter period in ponds of drought prone area. Sustainability of this technique, however, is constrained by high feed cost and poor water quality. Therefore, as an overcoming effort, three diets (protein content of 20%, 25% and 30%) under three different treatments (T1, T2 and T3) were tested during January-June, 2020 in fattening ponds of carps (Catla, Gibelion catla; silver carp, Hypophthalmichthys molitrix; rohu, Labeo rohita; mrigal, Cirrhinus cirrhosis; and carpio, Cyprinus carpio var. specularis) under Rajshahi district, Bangladesh. Variation in protein level had no significant effect on environmental parameters of pond water. Combined fish yield was found to vary significantly (P<0.05) among the treatments, while feed conversion ratio did not vary significantly. Although second degree polynomial regression analysis identified 28.50% dietary protein for optimal growth of carps but no significant difference between T2 and T3 was found for the total fish yield. However, significantly (P<0.05) highest cost-benefit ratio obtained with the diet containing 25% protein suggested this protein level in diet was profitable for carp fattening in pond.

Statistical Analysis of Seasonal Rainfall Variability and Characteristics in Ahmednagar District of Maharashtra, India

The three major characteristics of rainfall are mainly its amount, frequency and intensity. The value of rainfall varies greatly from day to day, place to place, month and year to year. Generally Akole tehsil receives the highest rainfall and Karjat and Jamkhed tehsils receives the least rainfall. The main reason for the highest rainfall in Akole tehsil is orographic type rainfall. The rainfall characteristics and distribution in drought prone area in study area. The research covers rainfall data from 1981 to 2014 and the rainfall data is taken from the statistical department website of Ahmednagar district.

ASSESSMENT OF EARLY SEASON AGRICULTURAL DROUGHT USING REMOTE SENSING

Drought is a stochastic natural hazard that is caused by intense and persistent shortage of precipitation. The initial shortage of rainfall subsequently impacts the agriculture and hydrology sectors. Marathwada region of India comes under highly drought prone area in the country. Recent times have shown the increase in occurrence of agricultural drought in the non-monsoon season. The deviation from normal rainfall in the month of October causes soil moisture deficit which triggers an agricultural drought in the early-Rabi season. The traditional remote sensing based agricultural drought monitoring indices lack in identifying the early-season (ES) drought. An attempt has been made in the present study, to map ES agricultural drought in the Aurangabad district of Marathwada region using remote sensing. The meteorological deficit in the month of October, has been assessed using Standardized Precipitation Index (SPI). Impact of meteorological fluctuations on agricultural system in terms of dryness/wetness was evaluated using the Shortwave Angel Slope Index (SASI) derived using MODIS (Terra) Level-3, 8 daily, surface reflectance data for the October months of 2001–2012. It was observed that the area experiences moderate to severe drought 5 times with 12 years of study period (2001–2012). SASI and its parameters were estimated for each week of October month. SASI maps were further classified in four categories viz. moist vegetation; dry vegetation; moist soil and dry soil. The detailed analyses if these maps indicate that agricultural stress occurs in this area even if there is no meteorological stress. However, whenever, there is meteorological stress the area under agricultural stress exceeds more than 50% of the study region. A frequency distribution map of ES drought was prepared to identify the most drought prone area of the district and to alternately identify the irrigated area of the district.

Soybean-maize intercropping feasibility under drought-prone area in East Java, Indonesia

Harsono A, Elisabeth DAA, Muzaiyanah S, Rianto SA. 2020. Soybean-maize intercropping feasibility under drought-prone area in East Java, Indonesia. Biodiversitas 21: 3744-3754. The study aimed to determine the land productivity, economic feasibility, and soybean cultivar which is suitable for intercropped with maize in maize production center on dryland-upland in East Java, Indonesia. The study was conducted in Semanding and Merakurak Sub-districts, Tuban District, East Java, Indonesia at the end of rainy season (March-July 2019). The study used a factorial randomized block design with three replications. The first factor was planting patterns, namely: soybean intercropping with maize, maize monoculture, and soybean monoculture. The second factor was soybean cultivars, namely: Argomulyo, Dena 1, and Dega 1. The maize variety used was NK Hybrid 212. The result of study indicated that by intercropping and selecting appropriate cultivar, soybean could be developed on dryland-upland area. Soybean intercropping with plant spacing of 30 cm x 15 cm and two seeds per-hill and maize in double row with plant spacing of (40 x 20) cm x 200 cm and one seed per-hill was able to produce maize seeds yield as high as maize increase LER by 1.69, and increase farming income. Dena 1 intercropping with maize was able to provide higher benefit, economic feasibility, and land-use efficiency than Argomulyo and Dega 1, even though Dega 1 had the strongest competitiveness, and Argomulyo had the higher soybean yield.

Immature growth performance of three important rubber tree (Hevae brasiliensis) clones in a drought-prone area

Adaptation of rubber tree clones to water-limited areas and maintenance of trunk radial growth are important keys for performance of genetic material. The rubber farmers need to shorten the interim phases to produce latex, which is considered “immature” phase, i.e. the time without income. The objective of this study was to compare the performance of three important rubber tree clones: GT1, the elder clone as control, which is still widely used in Cambodia and West Africa; RRIM600, the “all-round” clone, the most planted clone in Thailand, the first world producer; and RRIT251, the expanding clone, recommended by the Rubber Authority of Thailand, all in the field condition. The investigation was conducted in a drought-prone area of Northeast Thailand, where the dry season lasts 5 to 6 months. The cumulated growth and the annual growth were analyzed 4.5 years after planting. The trunk girth and height were measured monthly. Main climatic variables were hourly recorded. The year was separated in three periods: the leaves-shed season from January to April, the wet season from May to September, and the dry season with canopy maintenance from October to December. The results showed significant clonal effect on both trunk girth and height; however, with relatively low differences. The trunk girth of clone RRIT251 was about 29 cm and 10% higher than GT1. The difference was not significant in RRIM600. The annual girth increment was mainly located in wet season (63%) without clonal effect. The clonal difference was occurred in the dry season, where RRIT251 was better performed particularly in the leave-shed period preceding wet season. On a monthly basis, the relative trunk girth increment rate was highly negatively related to the vapor pressure deficit. We hypothesized that rubber clones shared a common strategy of dehydration avoidance, while RRIT251 expressed a little less degree of avoidance.