Effect of Cover Crops, Lime and Rock Phosphate on Maize (Zea mays L.) in an Acidic Soil of Northern Guinea Savanna of Nigeria

Phosphorus deficiency is the major constraint to maize production in acidic soil of Heipang (9°38’, 8°53’) in Northern Guinea Savanna of Nigeria. The soil is high in sesquioxides and soluble aluminum and has high phosphate sorption capacity. To address this problem, a field trial was conducted between 1996-1997 to assess the responses of six tropical cover crops and maize to lime and applied rock phosphate and to evaluate the effect of these treatments on the performance and P nutrition of succeeding maize. Results of the trial showed that planting Chamaecrista rotundifolia, Lablab purpureus, Mucuna pruriens, and maize-Chamaecrista rotundifolia intercrop reduced the leaf Al concentration of succeeding maize by more than 38%. Although none of the six cover crops significantly increased grain yields of succeeding maize, C. rotundifolia was the most consistent in improving maize performance while Glycine max produced the least performance. Concentration of Mn in the index leaves of maize was significantly higher on plots where G. max preceded maize, thus accounting for the poor performance of maize on these plots. Application of Sokoto Phosphate Rock at 30 kg ha^(-1) to cover crops produced very significant improvement in the yields of succeeding maize. While liming with 1.35 t CaO ha^(-1) in 1997 raised the soil pH value by 0.2 and significantly improved total P uptake by maize

Legume rotation in the moist tropical savanna: managing soil nitrogen dynamics and cereal yields in farmers' fields

The contribution of root and leaf litter to soil nitrogen dynamics, nitrogen uptake and balance was evaluated under cereal–legume rotations in a tropical moist savanna soil. Two legumes, soyabean (Glycine max) and stylo (Stylosanthes hamata), and maize (Zea mays) as a control were grown in four farmers' fields of different native fertility in 1993. At the end of the season, soyabean grain and stover were harvested and stylo biomass was removed for fodder. At the beginning of the 1994 season levels of total mineral nitrogen at a soil depth of 0–30 cm were 75, 52 and 44 kg ha−1 following soyabean, stylo and maize respectively. Total nitrogen uptake by maize was over 25% higher following legumes than following maize. Maize yield was 20 and 24% higher when grown after stylo and soyabean than after maize in spite of the removal of the standing legume biomass from the plots. Sorghum grain yield and nitrogen uptake were not significantly affected by the previous crops. Nitrogen balance estimates indicated that loss of nitrogen, probably due to leaching, was lowest in the plots previously planted with stylo. Results indicated opportunities to integrate appropriate legume-based technologies into the farming systems based on an identification of inherent nitrogen-release patterns

Growth and distribution of maize roots under nitrogen fertilization in plinthite soil

To improve efficiency of soil N and water use in the savanna, maize (Zea mays L.) cultivars with improved root systems are required. Two rainfed field experiments were conducted in Samaru, Nigeria in the 1993 and 1994 growing seasons with five maize cultivars under various rates of nitrogen fertilizer. The capacity of maize for rapid early root growth and to later develop a deep, dense root system was assessed. In addition, the effect of N fertilization on root growth of maize was studied in 1994. The widely cultivated cultivar TZB-SR had a poor root system in the surface soil layer and was more susceptible to early-season drought, as indicated by low plant vigor and aboveground dry matter yield during that time. It had a lower grain yield and a relatively small harvest index, but ranked among the highest in total aboveground dry matter production compared to other cultivars. The size of root system alone did not always relate well with grain yield among cultivars. Partitioning of dry matter within the plant was important in determining differences in grain yield and N stress tolerance between cultivars. A semiprolific cultivar (SPL) had high seedling vigour and a dense root system in the surface soil layer that conferred a greater tolerance to early-season drought stress and improved uptake of the early-season N flush, as indicated by a greater dry matter yield at 35 days after sowing (DAS). It also had a fine, deep, dense root system at flowering that could have improved water- and N-use efficiency in the subsoil (> 45 cm), thereby avoiding midseason drought stress in 1994. SPL had a large harvest index and the greatest yield among cultivars in 1994. Averaged across cultivars, greater root growth and distribution was observed at a moderate N rate of 0.56 g plant−1 than at zero-N or high N (2.26 g plant−1). Differences in root morphology could be valuable as selection criteria for N-efficient and drought-tolerant maize

ОЦІНКА УЩІЛЬНЕННЯ ҐРУНТІВ ЯК МАНІПУЛЯТИВНА СТРАТЕГІЯ ДЛЯ ПОКРАЩЕННЯ ЇХ БІОРІЗНОМАНІТТЯ: ПІДХІД ДО ВИКОНАННЯ ЦІЛЕЙ СТАЛОГО РОЗВИТКУ (SDG) ДВА ТА ШІСТЬ

The rapid increase in soil deterioration has been a drawback to global development, acting like a barrier to sustainability of Agriculture and the environment. Biodiversity in soil plays a crucial role in ecosystem sustainability, but yet there exist a rapid deterioration in soil biodiversity especially due to increase soil toxins, chemical spills, wind erosion including the rapid down-pour by rainfall which destroys soil structure and degrade soil biota. Soil compaction reduction manipulation through tillage and application of fertilizer plays a major role for food production, apart from being a part of environmental sustainability strategy. Field studies was conducted, where the status of soil compaction was examined, a replicate of four (4) soil sample were collected at a twenty (20) points sampling station using the proportionate stratified random sampling technique. Laboratory analysis output indicated high soil compaction. Laboratory analysis output was ranked with FAO standardize rate for compaction effect on soil biodiversity. Result of the finding indicated high soil compaction with bulk density value range of 1,56 gcm-3 – 2,71 gcm-3  which was found to be too compact for sustainable soil biota development. And porosity value range of 1% - 41% was obtained, which indicated tight soil spore that can imped soil biodiversity. Correlation analysis (R2) revealed a positive correlation between topography and soil compacting, with a ranking output of the soil been poor in biodiversity (biota load). Outcome of this investigation concluded that proper tillage, application of fertilizer including organic matter be carried out for the study area soils and soils of its environs.Швидке зростання погіршення стану ґрунту стало негативним наслідком глобального розвитку, виступаючи перешкодою для сталого розвитку сільського господарства та довкілля. Біорізноманіття ґрунтів відіграє вирішальну роль у стійкості екосистем, але все ж спостерігається його швидке погіршення, особливо через збільшення токсичного та хімічного забруднення грунтів, вітрової ерозії, включаючи сильні зливи, що руйнує структуру ґрунту та погіршує ґрунтову біоту. Дії, які сприяють зменшенню ущільнення ґрунтів за рахунок обробітку ґрунту та застосування добрив відіграють головну роль у виробництві продуктів харчування, крім того, є частиною стратегії екологічної стійкості. Були проведені польові дослідження, де було досліджено стан ущільнення ґрунту. На двадцяти (20) точках відбору проб зібрано зразки грунту в чотирикратній (4) повторюваності, використовуючи пропорційну стратифіковану методику випадкового відбору проб. Результати лабораторного аналізу показали високе ущільнення ґрунту. Результати лабораторного аналізу оцінювали за нормою стандартизації ФАО щодо впливу  ущільнення на біорізноманіття ґрунтів. Результати показали високе ущільнення ґрунту з діапазоном значень обємної щільності складення 1,56 г см-1 - 2,71 г см-1, що було занадто щільним для сталого розвитку ґрунтової біоти. Було отримано діапазон значень пористості 1% - 41%, що вказувало на щільну спорову структуру ґрунту, яка може перешкоджати біорізноманіттю ґрунту. Кореляційний аналіз (R2) виявив позитивну залежність (кореляцію) між рельєфом та ущільненням ґрунтів, причому результати ранжування грунтів були досить бідними щодо біорізноманіття (навантаження біоти). Результати цього дослідження дали можливість зробити висновок, що для досліджуваних і прилеглих ґрунтів слід проводити належну обробку ґрунту, вносити добрива, включаючи органічні речовини

Predictive analytics for the Vipulanandan rheological model and its correlative effect for nanoparticle modification of drilling mud.

Modelling the flow of nanoparticle modified drilling mud (or nano-drilling muds) requires the use of existing generic time-independent models with the addition of nanoparticle terms having a number of parameters incorporated. These parameters quantify the uncertainties surrounding nanoparticle contributions to drilling mud rheology. However, when the parameters in the overall model become too large, the tuning of each parameter for proper flow description can be challenging and time-consuming. In addition, the predictive capability of known models for the different regimes associated with the flow of nano-drilling muds is limited in scope and application. For example, computational analysis involving nano-drilling muds have been described using Herschel-Buckley, Power-Law, Bingham Plastic, Robertson-Stiff, Casson, Sisko, and Prandtl-Eyring. However, these models have been shown over time to have limited predictive capability in accurately describing the flow behavior over the full spectrum of shear rates. Recently, a new rheological model, the Vipulanandan model, has gained attraction due to its extensive predictive capability compared to known generic time-independent models. In this work, a rheological and computational analysis of the Vipulanandan model was carried out with specific emphasis on its modification to account for the effects of nanoparticles on drilling muds. The outcome of this novel approach is that the Vipulanandan model can be modified to account for the effect of interaction between nanoparticles and clay particles. The modified Vipulanandan show better prediction for a 6.3 wt% mud with R2 of 0.999 compared to 0.962 for Power law and 0.991 for Bingham. However, the R2 value was the same with Herschel Buckley model but the RMSE value show better prediction for the Vipulanandan model with a value of 0.377 Pa compared to the 0.433 Pa for Herschel Buckley model