Evaluation of Wheat (Triticum aestivum) and Legume Intercropping Under 1:1 and 2:1 Row-replacement Series System

A field experiment was conducted during the winter season of 1992–93 and 1993–94 at Agricultural Experimental Farm, Giridih, Bihar to evaluate the intercropping systems of legumes, gram ( Cicer arietinum L.), pea ( Pisum sativum ) and lentil ( Lens culinaris ) with wheat ( Triticum aestivum ) in 1:1 and 2:1 'row replacement series'. Intercropping systems were assessed on the basis of new indices termed as actual yield loss (AYL) and intercropping advantage (IA). This paper highlights the comparative effectiveness of evaluating the intercropping systems through the existing intercropping indices like LER, RCC, aggressivity. The indices AYL and IA seem to be more appropriate particularly when per plant yield is considered. Intercropping reduced the yield of component crops compared with respective pure stands. Wheat + pea in 1:1 row replacement series gave the highest wheat yield equivalent value (3.02 t ha⁻¹) followed by wheat + lentil (2.91 tha⁻¹). When the actual sown proportion was considered wheat + lentil (1:1) resulted in maximum AYL (+0.610) and IA (+0.279) values. This treatment also gave the maximum monetary advantage (Rs 5985.45 ha⁻¹).     

Measurement of nitrate leaching losses from arable plots under different nitrogen input regimes

Abstract. Leaching losses of nitrate-nitrogen were measured from a set of eight hydrologically isolated plots on a clay loam soil over the period from September 1987 to February 1990. Variable drainflow recovery from the plots hampered accurate estimation of nitrate loading, but results suggest that, when inorganic nitrogen fertilizer is applied up to the recommended amount, there is little influence of the amount applied on the amount leached. We did, however, observe the following effects on nitrate leaching: leguminous green manure incorporated in autumn increased leaching of nitrate-nitrogen by 10–15 kg per hectare during the winter; autumn cultivation caused some increase in leaching compared with no cultivation in one year; some systematic variations in nitrate leaching occurred between years and between plots, but were unrelated to treatments.
From the results we conclude that green manuring does not provide sufficient nitrogen for organically grown crops on this soil but contributes significantly to nitrate leaching, and that growing spring cereals, with the land remaining in stubble as long as possible in autumn, may be the best strategy to minimize nitrate leaching.     

Salinity Effects on the Growth and Ion Contents of Some Chickpea (Cicer arietinum L.) and Lentil (Lens culinaris Medic.) Varieties

The effect of salinity on seed germination, plant yield parameters, and plant Na, Cl and K concentrations of chickpea and lentil varieties was studied. Results showed that in both crops percentage emergence was significantly reduced by increasing NaCl levels (0–8dSm^?1). From the plant growth studies it was found that differences existed among chickpea and lentil varieties in their response to NaCl application. In chickpea, the variety Mariye showed the comparatively lowest germination percentage and the lowest seedling shoot dry weight in response to salinity and was also among the two varieties which had the lowest relative plant height, shoot and root dry weight and grain yield at maturity. Similarly, variety DZ-10-16-2, which was the second best in germination percentage and the highest in terms of seedling shoot dry weight, also had the highest relative plant height, shoot and root dry weights, and grain yield at maturity. In lentil, however, such relationships were less pronounced. Chloride concentration (mg g^?1) in the plant parts at salt levels other than the control was about 2–5 times that of Na. K concentration in the plants was significantly reduced by increasing NaCl levels. Chickpea was generally more sensitive to NaCl salinity than lentil. While no seeds were produced at salinity levels beyond 2dSm^?1 in chickpea (no seeds were produced at this salt level in the most sensitive variety, Mariye), most lentil varieties could produce some seeds up to the highest level of NaCl application. Overall, varieties R-186 (lentil) and Mariye (chickpea) were the most sensitive of all varieties. On the other hand, lentil variety NEL-2704 and chickpea variety DZ-10-16-2 gave comparatively higher mean relative shoot and root dry weights, and grain yield, thus showing some degree of superiority over the others. The observed variations among the varieties may be useful indications for screening varieties of both crops for salt tolerance.     

Purification and characterization of hepatic triacylglycerol lipase isolated from rainbow trout,Oncorhynchus mykiss

Trialcylglycerol (TG) lipase was isolated and partially purified from rainbow trout liver. Triacylglycerol lipase activity was assayed by measuring¹⁴C-oleic acid release from¹⁴C-triolein.¹⁴C-oleic acid release was linear for up to two hours. Optimal activity occurred at pH 7.0 and 15°C. Most of the lipase activity was recovered in the cytosolic fraction. A 27,000-fold purification was achieved after Sepharose (Bio-gel A 0.5 M, 200–400 mesh) chromatography of a resuspended 20% ammonium sulfate fraction. The molecular weight of the trout hepatic lipase as determined by size-exclusion chromatography and by SDS-polyacrylamide gel electrophoresis was 40–43 kD. Lipase-mediated hydrolysis of TG resulted in the production of diacylglycerols, monoacylglycerols, and fatty acids. Kinetic analysis indicated that V_max=0.016 nmol/h/mg protein and that K_m=0.28 mM triolein. Lipolytic activity was enhanced in the presence of cAMP/ATP-Mg²⁺. These results suggest that the liver of trout possesses a neutral TG lipase that is responsible for mobilizing stored TG and is catalytically activated by phosphorylation.A part of this work was presented at the Annual Meeting of the American Society of Zoologists, December 26–30, 1990, San Antonio, TX.     

Influence of Low Light Irradiance on Grain Filling in Rice (Oryza saliva L.) cultivars

Time course of grain filling pattern in two rice (Oryza sativa L.) cultivars, grown under normal and low light intensities, was studied. The number of spikelets, partially filled grains and high density grains were monitored at a 5 day interval during grain filling period from uniform panicles tagged at anthesis. The low light tolerant cultivar Swarnaprabha had more high density grains and less partially filled grains throughout the grain filling period and at harvest compared to cultivar Ratna under both normal and low light intensities. Further, the opening of spikelets in two flushes in Swarnaprabha seemed to result in a more efficient resource allocation and hence better yield as compared to Ratna, in which the opening of spikelets was in a single flush on day 10.     

Prototype agricultural land evaluation systems for Canada: I. Overview of systems development

Abstract. Information on land resources and the capacity of land to support agricultural production is a prerequisite for the formation of sound agricultural policies. This paper summarizes Canadian experiences in developing national and regional land evaluation systems. Potential users expected the system to estimate the degree to which changes in biophysical and socio-economic conditions would alter options for land use and production, and to provide a context for more detailed analysis.
A broad-scale land evaluation system was designed to serve the needs identified by representative user groups. Two prototype systems were developed from available information to test the major features of the system design. Neither prototype was complete; one was national in extent and capable of addressing issues of national and provincial importance, the other covered a sub-provincial area but allowed for more detailed evaluation of the effects of soil modifying processes. A full range of applications was demonstrated using one or other of the prototype systems. As a result of this project, the broad-scale land evaluation system design was improved and verified, ongoing research and data collection activities were adjusted to ensure that they meet the needs of a macroscale land evaluation system, and approaches were developed to overcome problems of land evaluation system development.     

Metal toxicosis in horses.

The ubiquity and stability of metals in the environment make them unique as a pollutant or an essential dietary component. Metals are neither created nor destroyed by chemical processes but are redistributed in the environment. In combination with other elements, metal compounds and alloys are essential materials of the contemporary world. Inappropriate use or distribution in the environment leads to adverse health effects on all biologic systems, including horses. Gastrointestinal upset is a common feature of acute toxicosis with metals in general. Among the metals discussed, arsenic and inorganic mercury have a propensity to do severe damage to the gut. Deposition of cadmium on forage is the source most likely to intoxicate horses. This subchronic to chronic problem in horses is manifest as disease of the musculoskeletal system and kidneys. Iron-containing hematinics are widely used in racetrack horses and occasionally result in hepatopathy when excessive doses are administered. Lead continues to be recognized as the most significant environmental metal pollutant. Poisoning is encountered routinely in humans and animals. Of the animal species of veterinary concern, lead-poisoned horses are not a frequent encounter. Lead-intoxicated horses show signs of peripheral neuropathy (laryngeal hemiplegia), intermittent colic, and mild anemia. Acute mercury poisoning sometimes occurs from the common use of mercury-containing blistering agents, with most clinical findings related to acute renal failure. Chronic excessive intake of zinc by horses is uncommon but devastating in rapidly growing foals. The mechanism of chronic zinc toxicosis is coupled to the induced copper deficiency. The condition is a disease of cartilage in the articular and growth physes.     

Mitigation of N2O emissions from grassland by nitrification inhibitor and Actilith F2 applied with fertilizer and cattle slurry

Abstract. Nitrous oxide (N₂O) is involved in both ozone destruction and global warming. In agricultural soils it is produced by nitrification and denitrification mainly after fertilization. Nitrification inhibitors have been proposed as one of the management tools for the reduction of the potential hazards of fertilizer-derived N₂O. Addition of nitrification inhibitors to fertilizers maintains soil N in ammonium form, thereby gaseous N losses by nitrification and denitrification are less likely to occur and there is increased N utilization by the sward. We present a study aimed to evaluate the effectiveness of the nitrification inhibitor dicyandiamide (DCD) and of the slurry additive Actilith F2 on N₂O emissions following application of calcium ammonium nitrate or cattle slurry to a mixed clover/ryegrass sward in the Basque Country. The results indicate that large differences in N₂O emission occur depending on fertilizer type and the presence or absence of a nitrification inhibitor. There is considerable scope for immediate reduction of emissions by applying DCD with calcium ammonium nitrate or cattle slurry. DCD, applied at 25 kg ha^–1, reduced the amount of N lost as N₂O by 60% and 42% when applied with cattle slurry and calcium ammonium nitrate, respectively. Actilith F2 did not reduce N₂O emissions and it produced a long lasting mineralization of previously immobilized added N.     

Experimental and natural infection with the enzootic leukosis virus of cattle

A trial was performed with heifers at the age of six to seven months. The animals were experimentally infected with the lymphocytes of a virus-productive donor. Infection was produced in all the nine cases, as demonstrated by means of the positive syncytial test. As indicated by the results of the trial, the antibodies to the enzootic bovine leucosis virus (BLV) were produced soon after experimental infection. A high sensitivity of the serum-neutralization test and the ELISA method was demonstrated in this connection: by these methods, the antibodies were identified already two to three weeks after experimental infection whereas by the immunodiffusion test they could be detected only after five weeks. Twenty-four animals were exposed to natural contact infection. Within 270 days of the trial, the disease after contact was recorded only in one heifer out of the four that were in close contact with the experimentally infected animals. In this case, as compared with experimental infection, the antibodies were produced much later--after 85 to 93 days. Leucosis was recorded in none of the remaining animals. The reasons why such a favourable result was obtained were the thorough disinfection of the stables after blood collections and the strict observance of the aseptic conditions. The results of experimental infection in three cows were identical with those obtained in young cattle. In the experimentally infected dairy cows, antibodies in milk were determined by the ELISA method. As found, in milk the antibodies to BLV appear two to three weeks later than they do in serum. The ELISA method of BLV antibody detection can be used for the identification of infected animals in herds where enzootic bovine leucosis occurs.