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Huck Ywih Ch'ng Nik Muhamad Ab. Majid Mohamadu Boyie Jalloh 《Compost science & utilization》2017,25(2):82-94
Phosphorus is an essential element required to maintain profitable crop production. Most soils of the tropics, such as Ultisols, are acidic and fix phosphorus because of their characteristically high contents of aluminium and iron. Compost and biochar could be used to mitigate phosphorus fixation by reducing the phosphorus sorption sites. This study aimed to: (i) improve soil phosphorus availability, nutrient uptake, and yield of maize using biochar and pineapple leaf residue compost; and (ii) determine if the use of biochar and compost could exert a residual effect on phosphorus nutrition in the second cycle of the field trial. Field trials were carried out using a Zea mays L. hybrid as the test crop. At harvest, the plants were harvested, partitioned into leaves and stems, and analyzed. Soil samples were also collected and analyzed. Ears were harvested to determine the yield from each treatment. The results suggest that the soil total phosphorus and available phosphorus recovered from the treatments with the organic amendments were higher compared with the non-organic amendments. The availability of soil nutrients (nitrogen, potassium, calcium, magnesium, and sodium) in the soils and yield of maize were higher in the treatments with the organic amendments in the first and second field trials. These results further confirm that amending chemical fertilizers with organic amendments have a larger residual effect than chemical fertilizers only. Amending chemical fertilizers with organic amendments can be used to ameliorate phosphorus fixation of acid soils to improve maize production on acid soils. 相似文献
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Effect of Nitrogen Fertilizer Forms on Growth,Photosynthesis, and Yield of Rice Under Cadmium Stress
ABSTRACT A pot experiment was conducted to study the influence of four nitrogen (N) fertilizer forms [Urea; calcium nitrate, Ca(NO3)2; ammonium sulfate, (NH4)2SO4; and organic N] on growth, photosynthesis, and yield of rice under two cadmium (Cd) levels (0 and 100 mg Cd kg?1 soil). Cadmium addition significantly reduced photosynthetic rate, and the reduction varied with N fertilizer form, with ammonium (NH4 +)-N and urea treated plants having more reduction. Nitrogen form had a distinct effect on SPAD value, and the effect was also dependent on Cd level and growth stage. Cadmium-stress significantly reduced flag leaf area, but for the second leaf, only the plants supplied with organic N showed the reduction. There was a significant difference in plant height among four N forms, with NH4 +- and nitrate (NO3 ?)-treated plants having the highest and lowest height, respectively. Cadmium stress caused significant reduction in grains per panicle and total plant weight, and the reduction varied with N form, with organic N treatment showing more reduction. There were significant differences among N forms in N and Cd concentrations of the plants subjected to Cd stress, with NH4 +-N treated plants having highest N and lowest Cd concentrations and NO3 ?-treated plants having lowest N and highest Cd uptake. The results showed that the inhibition of Cd stress on growth and yield formation of rice is closely related to N fertilizer form. 相似文献
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Ibrahim Silas Akos Mohd Y. Rafii Mohd Razi Ismail Shairul Izan Ramlee Noraziyah Abd Aziz Shamsudin Asfaliza Ramli Samuel Chibuike Chukwu Senesie Swaray Momodu Jalloh 《水稻科学》2021,28(3):279-288
Improved rice lines were developed frome three parents with the resistance or tolerance to bacterial leaf blight, blast and drought stress, respectively, using single-, double- and three-way crosses. The improved lines were assessed for agro-morphological and yield traits under non-drought stress (NS) and reproductive-stage drought stress (RS) treatments. The mean comparison of traits measured between parent plants and progenies (improved lines) were similar, and there were significant and non-significant differences among the parents and improved lines (genotypes) under NS and RS. Smilarly, there was significant and non-significant differences in the interaction among both parent varieties and improved lines for NS and RS. Cluster and 3D-model of principal component analysis did not generate categorical clusters according to crossing methods, and there were no exclusive crossing method inclined variations under the treatments. The improved lines were high-yielding, disease resistant, and drought-tolerant compared with their parents. All the crossing methods were good for this crop improvement program without preference to any, despite the number of genes introgressed. 相似文献
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A study was conducted to assess the effects of the breakdown in internal infrastructure on the incidence of canine-transmitted human rabies in urban areas of Sierra Leone during the course of the civil war between 1995 and 2001. Data from provincial hospitals in the Western Area and Southern Province indicated that there was a significant increase in the incidence of canine-transmitted urban human rabies chi2 = 39.63, p < 0.0001, particularly among children chi2 = 23.73, p < 0.0001, over the course of the war. In the Western Area in 2001, towards the end of the war, there was a significant increase in adult cases, which was reflected in the observed versus the expected chi2 ratio (70 versus 53). Interview-based questionnaire surveys in Freetown administered between 2001 and 2002 indicated that dogs were commonly kept for security reasons, and were largely unrestrained and unlicensed, regardless of the socioeconomic status of the owner. Virtually all dogs were unvaccinated and were mainly living in close proximity with humans. This study indicated that there is an urgent requirement for appropriate mass rabies vaccination campaigns for pet dogs and for campaigns to manipulate the urban habitat to control free-roaming and wandering but owned dog populations in Freetown and other urban areas in the provinces of Sierra Leone. Interview-based questionnaires administered in three districts of Freetown indicated a relatively high degree of uniformity in dog husbandry and veterinary care habits across a wide range of socioeconomic status categories in dog owners. 相似文献
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