Impacts of Slow-Release Nitrogen Fertilizer Rates on the Morpho-Physiological Traits, Yield, and Nitrogen Use Efficiency of Rice under Different Water Regimes

The efficient use of water and fertilizer is vital for optimizing plant growth and yield in rice production. To achieve sustainable rice production and resource management, the ways in which applied water and nitrogen affect the root and shoot morpho-physiology, as well as yield, must be understood. In this study, a pot experiment was conducted to investigate the effects of slow-release nitrogen fertilizer (sulfur-coated urea) application at three levels (light nitrogen (NL), medium nitrogen (NM), and heavy nitrogen (NH)) on the growth, yield, and nitrogen use efficiency (NUE) of rice grown under three water regimes (wetting and soil saturation (WSS), wetting and moderate drying (WMD) and wetting and severe drying (WSD)). The results revealed that differences in water regimes and fertilizer rates led to significant differences in the roots, shoots, yield, and NUE of rice. Increasing the N dosage by 5% enhanced the root and biomass production by 16% in comparison with that of the other groups. The NH×WSS treatment produced the greatest root length, weight, density, active absorption, and oxidation. However, the integration of WSS × NL generated the maximum value of nitrogen apparent recovery efficiency (63.1% to 67.6%) and the greatest value of nitrogen partial factor productivity (39.9 g g−1 to 41.13 g g−1). Transmission electron microscopy (TEM) images showed that plants grown under high and medium nitrogen fertilizer rates with WSS had improved leaf mesophyll structure with normal starch grains, clear cell walls, and well-developed chloroplasts with tidy and well-arranged thylakoids. These results show that TEM images are useful for characterizing the nitrogen and water status of leaves in the sub-micrometer range and providing specific information regarding the leaf microstructure. The findings of this study suggest that the application of NH×WSS can produce improvements in growth traits and increase rice yield; however, the NL×WSS treatment led to greater NUE, and the authors recommend its usage in rice agriculture.

Soya Bitkisinin Gelişiminde Gübre, Kompost, Mikoriza ve Bakteri Uygulamalarının Etkileri

One of the most important factors that increase soil fertility is the amount of soil organic matter. One of the ways to increase soil organic matter is the addition of organic fertilizers. Yemsoy soybean cultivar was used in the study, and pot study was carried out in 3 replications according to the randomized blocks experimental design. In the study, three different fertilizer doses (EC 0- 0.5- 1), three different grape pomace compost (0- 20-40 %) were applied to the peat perlite mixture, and mycorrhiza and bacteria inoculation to these environments. At the end of a 60-day growing period, the plants were harvested from the top of the pot, and measurements were made. In the study, there was an increase in the above-ground fresh and dry weights, root fresh, and root dry weights of soybean plants grown with increasing fertilizer rates. The addition of compost to the growing medium, the addition of mycorrhiza, and bacteria caused different results in the investigated properties. The increase in compost and plant nutrition doses was effective in increasing plant growth.

Influence of urea fertilizer on early growth of African Rose Wood (Pterocarpus erinaceous Poir.) seedlings in Kaduna State, Northern Nigeria

Influence of urea fertilizer on early growth and development of Pterocarpus erinaceous seedlings were investigated. Two hundred (200) uniformly growing seedlings were transplanted into polythene pots filled with top soil. Four urea fertilizer rates (0.035; 0.065; 0.095; 0.0125 g) and control were applied to the seedlings in the pots 20 × 25 × 25 cm, filled with 800 g of top soil collected from forest plantation. Assessment on the metrical character of the seedlings was done fortnightly. The fertilization of the selected seedlings with urea fertilizer was done round the seedlings in the nursery pots using ring method. The experiment was laid out in a completely randomized design. The data were subjected to analysis of variance, and means were separated using Duncan’s multiple range test at p < 0.05. The results show that fertilizer rates had significant (p < 0.05) effect on the growth and development of seedlings of P. erinaceous. Seedlings treated with 0.095 g of urea produced the highest mean values of 12.00 ± 0.66 cm; 0.33 ± 0.01 mm; 190 cm2 and 12.65 ± 0.67 for stem height, collar diameter, leaf area (LA) and number of leaves respectively. Seedlings fed with 0.125 g had the lowest values of 11.19 ± 0.61cm for height, 0.32± 0.01 mm for collar diameter 11.54 ± 0.70 for number of leaves and 124 cm2 for the LA. Urea fertilizers had significant effect on the early growth of the seedlings, therefore fertilization at 0.095 g per pot is recommended for raising P. erinaceous seedlings.

Profitability and Impact of Inorganic Fertilizers on the Maize Production in Ekona, Cameroon

Summary Declining soil fertility and low fertilizer use are the major abiotic factors limiting the maize production in Cameroon. Therefore, the design and introduction of appropriate fertilizer schemes, which would improve maize yields and provide incentives for smallholder farmers, are considered imperative. In 2018, a field experiment was conducted on the farm of the Institute of Agricultural Research for Development (IRAD) in Ekona, the south-west region of Cameroon, to investigate the profitability and impact of inorganic fertilizers on maize production. The experiment was laid out in a randomized complete block design with four replications and four treatments, using different fertilizer rates per hectare in each treatment (namely unfertilized control (T1), 50 kg urea + 50 kg N-P-K (T2), 100 kg urea + 100 kg N-P-K (T3) and 150 kg urea + 150 kg N-P-K (T4)). The results obtained indicate that all the maize growth parameters (plant height, number of leaves per plant, stem girth and leaf area) and yield components considered (cob length, cob diameter and test weight of 100 grains) were significantly (P < 0.05) higher in T4 than T1. The grain yields recorded ranged from 4.09–5.88 t ha−1 and were also statistically (P < 0.05) higher in T4 than T1. The incremental income based on the fertilizer use was the highest in T4, followed by T3 and T2. The value cost ratio (VCR) was greater than 2 in all the treatments and was found to be highest in T2 (3.15), followed by T4 (2.52) and T3 (2.49). As T2, T3 and T4 did not differ statistically (P > 0.05), all the fertilizer rates considered were economically viable, but T4 provide the most cost-effective due to its higher grain yields and incremental income.