Effect of fertilization on crop responses and solute transport for rice crop in a sub-humid and sub-tropical region

In order to increase the efficacy of water and control the losses of fertilizer, it is necessary to assess the influence of level of fertilization on crop responses, movement and balance of water and solutes from fertilizers in the root zone. With this goal, the reported study was undertaken to determine the effect of fertilization on crop responses and fertilizer solute transport in rice crop field in a sub-humid and sub-tropical region. Field experiment was conducted on rice crop (cultivar IR 36) during the years 2003, 2004, and 2005. The experiment included four fertilizer treatments comprising different levels of fertilizer application. The fertilizer treatments during the experiment were: F₁ = control with N:P₂O₅:K₂O as 0:0:0 kg ha^?1; F₂ = fertilizer application of N:P₂O₅:K₂O as 80:40:40 kg ha^?1; F₃ = fertilizer application of N:P₂O₅:K₂O as 120:60:60 kg ha^?1 and F₄ = fertilizer application of N:P₂O₅:K₂O as 160:80:80 kg ha^?1. The results of the investigation revealed that the magnitudes of crop parameters such as grain yield, straw yield, and maximum leaf area index increased with increase in fertilizer application rate. The levels of fertilization had very little effect on water loss via deep percolation and water use by the crop. The levels of fertilization had considerable effect on N leaching loss and uptake of N whereas it had no significant impact on leaching loss of water-soluble phosphorus. This indicated that PO₄-P leaching loss was very low in the soil solution as compared to nitrogen due to fixation of phosphorus in soils. The results also revealed that increase in level of fertilization increased water use efficiency considerably by increased crop yield. From the observed data of nutrient use efficiency, crop yield and environmental pollution, the fertilization rate of N:P₂O₅:K₂O as 80:40:40 kg ha^?1 (F₂) was the most suitable fertilizer treatment for rice crop among studied treatments.     

从形态学特征和腐殖质组分谈内蒙古黑垆土的演化

黑垆土作为１个独立的土类,在内蒙古自治区南部温带地区分布有其特殊意义。该土类的形态学特征是具有深厚的暗褐色的腐殖质层,耕作层较黄土高原的黑垆土薄,无古老的耕作层;土体中有碳酸盐假菌丝状新生体、碳酸盐含量较低在１％上下。腐殖质含量较低在１％～３％,胡敏酸和富里酸比值在剖面中下部达到２以上,胡敏素相对含量较低,一般不超５０％。该区域分布的黑垆土是温带草甸草原黑钙土演变的结果。     

Teleconnection of rainfall time series in the central Nile Basin with sea surface temperature

We investigated teleconnections of rainfall time series in the central Nile Basin (Sudan and South Sudan) with localities in the global sea surface temperature (SST) field, using monthly rainfall data from 11 gauging stations from 1960 to 1999. Annual rainfall ranged from 100 mm in the north to more than 700 mm in the south, and all stations had a strong contrast between rainy and dry seasons with rainless dry periods of several months. Rainfall time series at the stations were categorized as strongly seasonal, with precipitation concentration index exceeding 16 and seasonality index exceeding 0.9. The rainfall stations were classified into four zones on the basis of annual rainfall, seasonality, and cross-correlations among the stations. We calculated cross-correlations of interannual rainfall time series in summer (July and August) with the global SST field. For short lag times (0 or 1 month), summer rainfall in Zones I and II (northern arid regions) had significant correlations with SST over the eastern Mediterranean Sea and southern Indian Ocean, summer rainfall in Zone III (semiarid region) had significant negative correlations with SST over the Indian Ocean, and summer rainfall in Zone IV (southern wet region) had significant correlations with SST over tropical areas and the southwestern Pacific Ocean. For long lag times (3–6 months), Nile Basin summer rainfall time series had significant correlations with SST in various regions of the Atlantic and Indian Oceans but not the Pacific Ocean. Rainfall in Zones I and II had positive correlations (significance level?<?0.01) with SST south of Greenland and around the Azores Islands and negative correlations with SST south of Madagascar; rainfall in Zone III had negative correlations with SST in parts of the Indian Ocean; and rainfall in Zone IV had significant positive correlations with SST southwest of South Africa and negative correlations with SST in the southwestern Indian Ocean. In sum, rainfall in three of the zones (I, II, and IV) had significant positive and negative correlations with SST in parts of the Indian and Atlantic Oceans. For each of these zones, one positive correlation and one negative correlation were selected and correlations with the time series of the difference between the two SST records were calculated. Correlations of Nile Basin rainfall with the SST differences were stronger than the original positive and negative correlations. The resulting time series of SST difference were applied to an artificial neural network to predict summer rainfall, yielding satisfactory correlation coefficients between the observed and predicted summer rainfall (r?>?0.70).     

Effects of water exchange protocols on water quality,sedimentation rate and production performance of Penaeus monodon in earthen ponds

This study was carried out in farmers' fields to quantify the total water and consumptive water use in grow‐out culture of Penaeus monodon under recommended package of practice with two different water management protocols: T₁, with no water exchange and T₂, with regulated water exchange. Treatment‐wise estimated total water use, was 2.09 and 2.43 ha‐m 122 day^?1, while the computed consumptive water use index (m³ kg^?1 biomass) was 5.35 and 6.02 in T₁ and T₂ respectively. Lower rates of water exchange (T₂) showed significantly improved (P < 0.05) crop performance in terms of performance index (19.75 ± 0.75), production‐size index (74.1 ± 3.4), survival rate (80.13 ± 1.7%) and productivity (2.44 ± 0.08 t) over the zero water exchange. The shrimp pond water quality suitability index (WQSI) infers that regulated water exchange (T₂) improved the overall suitability of water quality for shrimp culture. WQSI up to 90 days of culture ranged between 7.5–9.0 in T₂, needs little management while in the last month of rearing, it was good with moderate management requirements. Treatment‐wise sediment load ranged between 50.4–56.3 m³ t^?1 shrimp biomass. High intensity of water exchange and low apparent feed conversion ratio influenced in lowering the sedimentation rate. Regulated water exchange protocol (T₂) performed well (higher net total water productivity and net consumptive water productivity) against no water exchange (T₁). A higher OV:CC ratio (ratio of the output value to the cost of cultivation) indicated that T₂ had a distinct edge over the T₁ protocol.     

Increase in estrogen signaling in the early brain of orange-spotted grouper Epinephelus coioides: a mini-review

Despite neurosteroidogenic enzymes are playing important roles in the regulation of brain development and function, the potential link between brain and gonad by the action of steroid hormones during gonadal sex differentiation is still not clear in teleosts. In this mini-review, we summarized our understanding on the early brain development related to the synthesis of neurosteroids and receptor signaling during gonadal sex differentiation in protogynous orange-spotted grouper, Epinephelus coioides (functional females for the first 6 years of life and start to sex change around the age of 7 years) and protandrous black porgy (functional males for the first 2 years of life but begin to change sex during the third year). We found a similar profile in the increased expression of brain aromatase gene (aromatatse B or cyp19a1b), aromatase activity, estradiol (E₂), and estrogen signaling in the brain of both grouper and black porgy fish during gonadal sex differentiation. In contrast to mammals, teleost fish Cyp19a1b expressed in a unique cell type, a radial glial cell, which is acted as progenitors in the brain of developing and adult fish. In agreement with these pioneer studies, we demonstrated that the grouper cyp19a1b/Cyp19a1b was expressed in radial glial cells. Further, in vivo data in the grouper brain showed that exogenous E₂ upregulated Cyp19a1b immunoreactivity (ir) in radial glial cells. These data suggest the possible roles of Cyp19a1b and E₂ in early brain development which is presumably related to gonadal sex differentiation.     

Impact evaluation of SGSY on socio-economic development of women in aquaculture in Eastern Hills of Orissa

Statistical evaluation of the impact of the SwarnJayanti Gram Swarozgar Yojana (SGSY) on socio-economic development of women in aquaculture in Eastern Hills of Orissa was made. A sample size of 60 women self-help groups (WSHGs) was selected from Koraput and Rayagada districts by multistage stratified random sampling method. The data on socio-economic status of the WSHGs were collected from 2006–2007 to 2008–2009. The members of the WSHGs were interviewed to collect information on their financial contribution and its expenditure pattern. There was a high significant difference between two means in yield (410.9 kg/acre, 306.1 kg/acre), employment generation (387 man-days, 277 man-days), financial contribution by the members to their families (Rs. 3,265/-, Rs. 2,490/-) and expenditure on food (Rs. 953/-, Rs. 538/-) of two groups of WSHGs—the treatment group, i.e., WSHGs under SGSY and the control group. By evaluating the level of development of the WSHGs during 2008–2009, it is revealed that 27.8% of WSHGs under SGSY achieved high level of development in economic sector against 11.9% of WSHGs in the control group. Similarly, in social sector, the percentage of WSHGs in treatment group in the category of high level of development (33%) was higher as compared to the percentage of WSHGs in the control group (11.9%). No significant difference in the development level of empowerment was found between these two groups of WSHGs. The state government should take necessary steps for increasing literacy and technical trainings of the members of the WSHGs in addition to micro-finance for successful implementation of SGSY.     

Can rice cultivar with submergence tolerant quantitative trait locus (SUB1) manage submergence stress better during reproductive stage?

Cultivars with submergence tolerant quantitative trait locus (SUB1) greatly enhance submergence tolerance at vegetative stage. Whether such cultivar is better off or not at reproductive stage submergence is not known. Due to uncertainties in rainfall pattern and delayed monsoon, flooding at later stages corresponding to reproductive stage is very much common now. Therefore, the main goal of the present investigation is to work out the effect of submergence at reproductive stage on yield and yield attributes in three rice cultivars namely Swarna, Swarna-Sub1, and Baliadhan (a traditional rice cultivar showed similar reaction to SUB1). The present study envisages that submergence at reproductive stage greatly decreased the grain yield even though there was no mortality of plants. Yield reduction was greater at flowering stage followed by booting and panicle initiation stage. Swarna-Sub1 performed significantly better compared to Swarna when submergence was given at panicle initiation stage. Swarna-Sub1 and Baliadhan both maintained greater quantities of carbohydrate and total dehydrogenase activity yet the yield reduction was greater in Swarna-Sub1 compared to Baliadhan due to greater chalf formation in the former. The cultivar with SUB1 is quite better off at reproductive stage submergence. Baliadhan is superior to Swarna-Sub1.     

Effect of age and sex in determining cognitive ability in Vanaraja chickens

(1) To evaluate the cognitive ability of male and female Vanaraja birds, three hundred and sixty 1-d-old sexed chickens were reared under similar conditions in three treatment groups with 4 replicates in each group: 120 females in Treatment 1, 120 males in Treatment 2 and both males and females (60 + 60) as a mixed group in Treatment 3.

(2) To assess learning ability, the birds were trained in T- and Y-mazes and tested at 3-week intervals in 4 test schedules (21, 42, 63 and 84 d). The birds were put into tonic immobility (TI) in each test schedule.

(3) In each maze test, the latency to find the feed was regarded as a successful completion of the task. In the TI-test, the time taken to stabilise on a plane surface after swinging in the hanging cradle for 20–25 s was recorded.

(4) The results indicated that male birds appeared to be cognitively superior to females in terms of learning and cognitive evolution in all the mazes, but by d 84, the females performed as well as the males. With increasing age, spatial memory gathering and processing improved. In the TI-test, the effect of sex or grouping system had no significant effect on the performance of birds at the various ages.     

不同退化程度草甸草原土壤理化性质与地上生物量的关系

针对草原生态系统日益恶化的趋势,对呼伦贝尔不同退化程度草甸草原土壤的理化性质与地上生物量的关系进行了初步探讨。结果表明:土壤含水量、土壤磷、土壤速效氮、土壤有机质、地上生物量随着退化程度的增加显著下降,土壤钾、土壤容重(10²0 cm)随着退化程度的增加而显著提高。土壤铵态氮和土壤容重(020 cm)随着退化程度的增加而显著提高。土壤铵态氮和土壤容重(0¹0 cm)没有规律性变化,且土壤含水量、土壤容重、土壤有机物、铵态氮、速效氮、钾在不同退化程度之间都具有不同显著性差异。