Asian Journal of Soil Science and Plant Nutrition

Aims: This study was conducted to formulate appropriate fertilization scheme for some rice varieties used at University Income Generating Project (UIGP) sites of Central Mindanao University (CMU), Philippines and to determine the effects of organic and inorganic fertilizers on some soil chemical properties.

Study Design: Split-plot in Randomized Complete Block Design (RCBD) in three replications with 5 levels of inorganic and organic fertilizers as main plot factor and 3 rice varieties as sub-plot factor.

Place and Duration of Study: UIGP area of CMU, Musuan, Bukidnon, the Philippines from November 2015 to May 2016.

Methodology: Plots were laid out following Split-plot in RCBD in 3 replications. The 5 levels of Fertilizers were: no fertilizer (control), 90-60-60 kg NPK/ha, 2t vermicompost/ha, 45-30-30 kg NPK/ha + 2t vermicompost/ha and 90-60-60kg NPK/ha + 2t vermicompost/ha while the three rice varieties were: Matatag 11, NSIC Rc158 and NSIC Rc238. The initial characteristics of the soil served as the basis for the recommended rate of inorganic fertilizer application at 90-60-60 kg NPK/ha.

Results: Analysis of variance showed that interaction between the levels of fertilizers and varieties were not significant for all agronomic and yield parameters except the number of days to 50% flowering implying that the varieties had a similar response to the levels of fertilizers. Results revealed that the levels of fertilizers significantly affected plant height at 30 (P = 0.011) and at 50 days after transplanting, DAT (P = 0.006), productive tiller count (P = 0.002), % filled grains (P = 0.026), and grain yield (P = 0.003) while the varieties significantly differed in plant height at 50 DAT (P = 0.006), number of days to 50% (P = 0.001) and 100% flowering (P = 0.001), % filled grains (P = 0.039), 1,000 grain weight (P = 0.009) and grain yield (P = 0.044). When averaged across varieties, grain yields were increased by fertilizer application with 90-60-60 + 2t vermicompost/ha giving significant increase of 2.14 t/ha (vs control) and 90-60-60 kg NPK/ha, 2t vermicompost/ha, and 45-30-30 + 2t vermicompost/ha giving not significant increases of 1.26, 0.36 and 1.05 t/ha, respectively. NSIC Rc238 had the highest grain yield that was significantly higher than that of NSIC Rc158 but not with that of Matatag 11. Moreover, soil pH, organic matter and extractable phosphorus (P) contents of the experimental plots after harvest were significantly influenced by vermicompost and inorganic fertilizer application (P = 0.01) with plots applied with vermicompost exhibiting significantly higher pH values and organic matter contents compared to those plots with no fertilizer and those applied with inorganic fertilizers alone.

Conclusion: Findings of the study disclosed that vermicompost is an effective organic amendment to improve soil pH, soil organic matter content and rice productivity in Maapag soil and its application at 2t/ha in combination with 90-60-60 kg NPK/ha gave the highest grain yields of Matatag, NSIC Rc158 and NSIC Rc238 at 6.23, 6.10 and 6.75 t/ha, respectively that were higher than their average yields but lower than their maximum yields.

The potato crop is highly affected by soil-borne diseases motivating its continuous migration to non-cultivated areas. Bacterial wilt caused by Ralstonia spp. is one of the main diseases affecting the potato crop in Brazil, since the conventional production system, used throughout the country, promotes an ideal environment for proliferation of members of this pathogen complex. Studying alternative potato production systems aiming to improve the soil biological properties is necessary in order to avoid the continuous migration of the potato crop to new areas. The objective of this work was to evaluate different potato production systems, namely, the Paces an alternative potato production system and the organic potato production systems in contrast to the conventional production system, a soil from the Paces system sterilized through autoclaving and an undisturbed Atlantic rainforest soil regarding the soil suppressiveness to bacterial wilt caused by R. solanacearum. The experimental design was randomized blocks with three replications, arranged in a 4 x 4 + 1 factorial scheme, the main factor being the production system and the secondary factor corresponding to the doses of soil contaminated with R. solanacearum added to each treatment (0, 25, 50 and 75%). The additional treatment corresponded to the soil of the conventional system with high incidence of R. solanacearum. The soil suppressiveness to bacterial wilt is a biological process inhibited by autoclaving. The Paces and the organic potato production systems have a significant potential to suppress R. solanacearum in infested soil.

Soil acidic conditions and the decline in soil fertility are among the critical factors that constraint higher crop productivity in the Old Himalayan Piedmont Plain (OHPP), Bangladesh. The study was conducted to evaluate the effect of lime and manure on soil fertility, nutrients and yields of wheat, mungbean and rice. Experiments were done at Agricultural Research Station (ARS), Bangladesh Agricultural Research Institute (BARI) farm and farmer field over two consecutive years with the cropping pattern, namely wheat-mungbean-transplanted (T.) aman rice/monsoon rice. The varieties used were Bijoy for wheat, BARI mung6 for mungbean and Bina dhan7 for T. aman rice. There were nine treatment combinations with three lime levels (0, 1 and 2 ton dololime ha^-1) and three manure treatments (poultry manure, farmyard manure and no manure) with three replications. The rate of poultry manure was 3 t ha^-1 and that of farmyard manure was 5 t ha^-1. Nutrients from manure sources were supplemented with chemical fertilizers to adjust recommended dose. Lime was added to the first crop for entire two crop cycles and manures were applied to the first crop of each crop cycle. Soil pH increased by 0.5-1.11 units, the higher values were observed with higher rates of lime application. Soil organic matter (SOM) increased slightly due to manure treatment. Soil phosphorus availability increased, zinc and boron availability decreased, but the potassium and sulphur availability remained almost unchanged after liming. Application of lime and manure had significant positive effect on the yield of wheat, and their positive residual effects on mungbean and T. aman rice. The effect of 1 t lime ha^-1 was comparable with that of 2 t lime ha^-1. Between two manures, poultry manure performed better than FYM on crop yields. The trend of plant nutrient uptake by wheat, mungbean and rice followed the trend of these crops yield increase, i.e., crops that were able to uptake more nutrients shown higher yields. The treatment combinations with 1 t ha^-1 lime and 3 t ha^-1 poultry manure produced an average 35-55% yield benefit over control for the first crop (wheat) and 41-43% yield benefit for the third crop (T. aman rice). This study suggests that dololime @ 1 t ha^-1 coupled with poultry manure @ 3 t ha^-1 or FYM @ 5 t ha^-1 would be an efficient practice for better soil acidic condition, soil fertility and productivity of crops in the Himalayan piedmont soil of Bangladesh.

Salt stress is one of the major abiotic stresses decreasing crop production, particularly in dry and semi–arid regions. Reclamation of salt–damaged soil is important as it is sweeping cultivable land day by day. Potassium is an essential element for plant development which is an extremely active ion in the soil system. Potassium is second to nitrogen in plant tissue levels ranging from 1 to 3% by weight. As a cation, potassium is highly mobile in plant and moderately mobile in the soil system. The essentiality of potassium is identified with its multiple roles in plants. Among these are the maintenance of cell turgor pressure and cell lengthening, osmoregulation, leaf and stomata movements, enzyme activation, phloem solute transport, cation/anion balancing, control of membrane polarization, cytoplasmic pH regulation, chloroplast structure and functioning, protein and starch synthesis, and energy preservation across membranes. As almost all of these processes are directly associated to plant adaptation to the in hospitable environment. It could be concluded that potassium uptake, transportation, and homeostasis play important role in conferring salt tolerance in plants.

Aims: To evaluate the possibility of allelopathic effects of the rotated crops on productivity, chemical composition, N utilization of wheat and soil fertility.

Study Design: A split plot design with three replications was used. The main plots were assigned with three previous crops, The sub plots were assigned by three nitrogen fertilizer rates (0, 35 and 70 kg N fed^-1).

Place and Duration of Study: A field study was carried out at Sakha Agricultural Research Station farm, ARC, Kafr El-Sheikh governorate, Egypt, during two successive seasons of 2016/2017and 2017/2018

Methodology: The local wheat cultivar (Sids 12) was sown after three crops (fahl berseem) after rice, (Drawa) after rice and Fallow after rice as preceded crops.

Results: The results showed that fahl berseem roots and residues in the clover (berseem)-wheat rotation secreted biologically active chemical compounds which have a positive effect on growth and development of wheat. The preceding clover (fahl berseem) wheat rotation appeared to be promising for wheat productivity, N, P, K concentrations, N-uptake, N utilization, protein content of wheat grain and straw, availability of N, P and K after wheat harvest compared with fallow after rice, green maize (drawa-wheat rotation). The interaction between the preceded crops and N fertilizer rates was significantly for all the studied traits. The highest performance of wheat traits were observed when wheat was grown after fahl berseem and fertilized with 70 kg N.fed^-1. While the lowest performance was obtained following cereal crops rice (fallow) and the lowest N level in both seasons. Treatment of fahl berseem with nitrogen fertilizer (70 kg N.fed^-1) had given a best values from grain yield with relative increments of (37.54%) compared with preceding rice-wheat rotation and (23.26%) compared with rice-drawa rotation.

Conclusions: Cereal winter crops can be sow after preceding legume crops rather than summer cereal crops. We can sow fahl berseem crop as a forage to animals after cereal crop (rice) and before sowing wheat crop to improve soil properties and its availability of the essential elements and consider additional revenue to farmer. Fahl barseem had be sown in the end of august month after rice crop to produce approximetly 20 ton fresh forage.fed^-1 (~ 9 ton dry grass.fed-1) which provides farmers with (~ 9 thousands EL) in 88 days only.