Efficient Agricultural Practices Research Articles

An Autonomous Wireless Device for Real-Time Monitoring of Water Needs.

The agri-food sector is in constantly renewing, continuously demanding new systems that facilitate farmers´ work. Efficient agricultural practices are essential to increasing farm profitability, and reducing water consumption can be achieved by real-time monitoring of water needs. However, the prices of automatic systems for collecting data from several sources (soil and climate) are expensive and their autonomy is very low. This paper presents a low-consumption solution using the Internet of Things (IoT) based on wireless sensor networks (WSNs) and long-range wide-area network (LoRaWAN) technologies. By means of low-power wide-area network (LPWAN) communication, a farmer can monitor the state of crops in real time thanks to a large number of sensors connected wirelessly and distributed across the farm. The wireless sensor node developed, called BoXmote, exhibits very low power, since it has been optimized both in terms of hardware and software. The result is a higher degree of autonomy than commercial motes. This will allow the farmer to have access to all of the information necessary to achieve an efficient irrigation management of his crops with full autonomy.

Nitrogen fertilization of soils fuels carbonate weathering and translocation in calcareous watersheds

In calcareous watersheds, groundwater alkalinity results largely from dissolution of carbonate minerals in soils. The alkalinity increases initially approximately in proportion to nitrate (NO3−) concentration and eventually approaches an apparent maximum of approximately 8 mmol L−1 at high NO3− concentrations. This close positive relationship between alkalinity and NO3− concentration appears to be predominantly a result of three processes: (i) mineralization of organic nitrogen fertilizer, (ii) exchange of OH− and H+ during the uptake of NO3− or ammonium by crop plants, and (iii) CO2 released by roots as a result of fertilizer-stimulated plant growth. We suggest that the asymptotic approach to a maximum groundwater alkalinity at NO3− concentrations exceeding 0.25 mmol L−1 may be caused by (i) a maximum possible areal crop production at excessive N fertilization and (ii) an increasing CO2 loss to the atmosphere due to the increasing CO2 production in the soil. Our analysis provides a general understanding and quantitative prediction of steady-state groundwater NO3− concentration, alkalinity, pH, the degree of CO2 supersaturation in the soil, and soil CO2 emissions to the atmosphere. The positive correlation between alkalinity and NO3− concentration observed in groundwaters persists in rivers and lakes. We conclude that an economically efficient agricultural practice that avoids over-fertilization might accelerate the in-soil carbonate weathering rate up to approximately threefold compared to unfertilized soils, but it will not jeopardize the use of aquifers for drinking water.

Calla lily intercropping in rubber tree plantations changes the nutrient content, microbial abundance, and enzyme activity of both rhizosphere and non-rhizosphere soil and calla lily growth

Rubber is a globally important crop species and is widely grown in Hainan, China; the development of efficient agricultural practices is essential when attempting to maximize productivity. The effects of interspecific competition for nutrients and calla lily (Alocasia macrorrhizos L.) intercropping on calla lily growth, development, and nutrient uptake were investigated in rubber tree (Hevea brasiliensis Müll. Arg.) plantations. The nutrient abundances, enzyme activity, and number of microbes present in rhizosphere and non-rhizosphere soil were determined. Barriers were inserted between the crops to separate their root systems and nullify belowground competition to facilitate the analysis of intercrop competition. We found that in the rubber tree/calla lily intercropping system, nutrient content and soil urease activities in rhizosphere and non-rhizosphere soil significantly decreased, and nitrogen (N) and potassium (K) taken up by calla lilies, and the growth and biomasses of calla lilies significantly decreased. In contrast, soil sucrase, acid phosphatase, and catalase activities and the quantity of fungi in rhizosphere and non-rhizosphere soil significantly increased, and phosphorus (P) uptake, root length, and the ratio of root to shoot dry weights in calla lilies also significantly increased. Intercropping significantly decreased the abundances of both bacteria and actinomycetes and decreased total microbial abundance in rhizosphere soil, but significantly increased their abundances in non-rhizosphere soil. The nutrient content (excluding organic matter content and pH) in rhizosphere soil was lower than in non-rhizosphere soil. These findings indicate that nutrient competition between rubber trees and calla lilies was significant in this intercropping system, with rubber trees holding a competitive advantage. Intercropping significantly inhibited calla lily growth by significantly decreasing soil nutrient content. The abundances of soil microbes and changes in root architectures correspond to the responses of calla lilies to nutrient competition, allowing the adjustment of the plants’ nutritional needs during growth and development.

Assessment of Water Supply–Demand Using Water Evaluation and Planning (WEAP) Model for Ur River Watershed, Madhya Pradesh, India

Many watersheds experience scarcity of water for agricultural and domestic use for most part of the year. Ur river watershed in Tikamgarh district of Madhya Pradesh, India, falls under a drought prone region of India. Water allocation and management are essential for sustainable agriculture for this region. Water Evaluation and Planning system (WEAP)-based decision support system can prove to be an effective tool for water allocation, supply and demand analysis. In the present study, spatially distributed model by using WEAP-MABIA method has been developed for analysis and simulation of agricultural water demands in the Ur river watershed. WEAP-MABIA method uses dual crop coefficient approach which helps in computing the separate soil evaporation and transpiration under various water availability situations. Year 2012–2013 is used as base year for customizing WEAP model for 8 subwatersheds. The model was calibrated using PEST tool, available in WEAP. The calibrated model was used for estimating future water demands and unmet demands by using future climate series, from 2015 to 2030, of IPCC scenario- RCP 4.5 of GDFL-ESM2M model. As per GFDLESM2M model (RCP4.5) predictions, rainfall is going to greatly vary in the coming years. The years 2020–2021 and 2028–2029 may experience very dry climatic conditions with 500 mm or less annual rainfall, while 2017–2018, 2023–2024 and 2025–2026 may experience heavy showers (1200 mm). Straight effects of this rainfall pattern could be seen in future water availability for agriculture and resultant crop yield. A high unmet demand exists in the case of agriculture since the first priority for water supply is meant to be for domestic purpose. Area under agriculture in Ur river watershed is large, while respective water supply is low. This gap puts an extra pressure on water resources leading to over extraction of groundwater and related problems. Looking at this scenario, water allocation requires great attention to narrow down the gap between existing demands and water supply. Since area under agriculture is large, water-efficient crops should be more emphasized. Also, efficient agricultural practices and rain water harvesting should be promoted in the study area. Since the watershed falls in semiarid condition and river flows are seasonal, different stress/deficit irrigation scenarios can be built using customized WEAP model to get higher yield.

In situ polymerization of soil organic matter by oxidative biomimetic catalysis

BackgroundAgricultural practices that enhance organic matter content in soil can play a central role in sequestering soil organic carbon (SOC) and reducing greenhouse gases emissions.MethodsWe used a water-soluble iron-porphyrin to catalyze directly in situ oxidative polymerization of soil organic matter in the presence of H2O2 oxidant, with the aim to enhance OC stabilization, and, consequently, reduce CO2 emissions from soil. The occurred SOC stabilization was assessed by monitoring soil aggregate stability, OC distribution in water-soluble aggregates, soil respiration, and extraction yields of humic and fulvic acids.ResultsSoil treatment with H2O2 and iron-porphyrin increased the physical stability of water-stable soil aggregates and the total OC content in small aggregates, thereby suggesting that the catalyzed oxidative polymerization increased OC in soil and induced a soil physical improvement. The significant reduction of CO2 respired by the catalyst- and H2O2-treated soil indicated an enhanced resistance of polymerized SOC to microbial mineralization. The catalyzed oxidative polymerization of SOC also significantly decreased the extraction yields of humic and fulvic acids from soil.ConclusionsThe oxidative catalytic technology described here may become an efficient agricultural practice for OC sequestration in soils and contribute to mitigate global changes.Graphical abstractCatalyzed polymerization of soil organic matter.

Assessment of Risk and Sustainability in Integration of Pig and Poultry Production into Cropping Systems in Rwanda

Subsistence animal production is rampant in Rwanda. The average size of land per household (0.72) is very low. Promoting efficient agricultural practices is key for realizing sustainable production of human feed and animal feedstuffs. Crops and livestock integration may be synergetic to production system yet they are often delinked probable due to ignorance of underling factors. This study aimed to identify cropping systems that can be appropriately integrated with pig/poultry production in Rwanda, and also assess the cropping systems for risk and sustainability. Results from a systematic household survey of pig and poultry farmers and secondary data were assessed by any expert team to determine the risk and sustainability associated with crop-integration. Maize, beans and cassava were found to be the feasible crops identified for integration with pig/poultry production out of the many staple food crops (beans, maize, banana, sweet potato, cassava, sorghum and vegetables). The negative risk level was estimated at 82%. Land fragmentation, low acreages, limited access to good quality planting and/or breeding materials, and poor access to knowledge/skills were the key risk drivers. The overall sustainability was fair (scored with an average of 3.4 on a scale of 1–5).

Large-scale assessment of optimal emergence and destruction dates for cover crops to reduce nitrate leaching in temperate conditions using the STICS soil–crop model

Cover crops can be an efficient agricultural practice to reduce nitrate leaching during the fallow period and decrease nitrate pollution of aquifers. For maximum reduction of nitrate leaching, cover-crop management must be adapted to the pedoclimatic context. We used the soil–crop model STICS to assess optimal emergence dates in summer and destruction dates in autumn and winter for three species of cover crops (mustard, ryegrass and vetch) at a large scale in France. We first calibrated and validated STICS’s predictions of soil and crop dynamics under a wide range of conditions, including bare soil and cover crops. Since predictions were sufficiently accurate, we then predicted the impact of several emergence and destruction dates of cover crops on nitrate leaching in 24 contrasting climatic sites over 20 years. These sites represented a wide range of conditions found in France and much of Europe. Using generalized linear model (GLM), we extrapolated to the vulnerable nitrate zones in France the optimal dates predicted for the 24 sites. We defined optimal emergence date as the date allowing the higher nitrate leaching decrease in drained water and optimal destruction dates as those for which a high reduction of nitrate leaching was predicted and that also avoided negative effects on the subsequent main crop and water resources. STICS accurately predicted mineral N and water dynamics from both calibration and validation datasets, despite lower accuracy for vetch simulations. Over the 20-year simulations, optimal dates varied, depending mainly on site, cover crop and year. Optimal emergence dates for cover crops were earlier for vetch (late July) than for ryegrass (early August) and mustard (late August) and earlier in the north (cold and rainy) than in the south of France (warm and dry). Optimal destruction dates, as defined in this paper, were frequently between October and December. Mean optimal dates by site and species were strongly correlated with climatic characteristics of the 24 sites tested, which enabled us to extrapolate them to a larger scale and identify areas with similar optimal emergence and destruction dates according to cover-crop species. Later optimal emergence dates occurred in southeastern France in late August and September, while the earliest dates occurred in late July and early August in the north and east of France. The extrapolated optimal destruction dates occurred in autumn (October–December), with later destruction dates located in zones with higher temperature in the western coastal zones of the Atlantic Ocean and in southeastern France.

Synthesizing of ethylene diamine dihydroxy phenyl acetic acid by use of formylation technique and characterizations of product by instrumental analyzing

Synthesis of iron chelating agents is a most efficient agricultural practice to control iron deficiency in agricultural products. Many identified reagents, especially ethylene diaminedihydroxy phenyl acetic acid, which help in releasing iron in plants, are used for the treatment of iron deficiency and of plants growing in calcareous soils. Ortho–ortho ethylene diaminedihydroxy phenyl acetic acid has the ability to mak a compound with iron which is better than its other isomers, such as its ortho–para and para–para isomers. In this research, ortho–ortho ethylene diaminedihydroxy phenyl acetic acid was synthesized by the formylation of phenol, whereas it is less attainable by previous methods. In this method, para-formaldehyde was first added to the magnesium phenoxide. After acid washing, the addition of ethylenediamine and hydrogen cyanide was begun. The hydrolysis of the products was carried out in the last stage, in which a red–brown solid was produced with an efficiency of 82 %. The structure and purity of the products were characterized through FTIR and MS analysis techniques. Interpretation of these spectra showed many new results in this research.

A Holocene pollen record from the northwestern Himalayan lake Tso Moriri: Implications for palaeoclimatic and archaeological research

This paper presents a new fossil pollen record from Tso Moriri (32°54′N, 78°19′E, 4512 m a.s.l.) and seeks to reconstruct changes in mean annual precipitation (MAP) during the last 12,000 years. This high-alpine lake occupies an area of 140 km2 in a glacial-tectonic valley in the northwestern Himalaya. The region has a cold climate, with a MAP <300 mm, and open vegetation. The hydrology is controlled by the Indian Summer Monsoon (ISM), but winter westerly-associated precipitation also affects the regional water balance. Results indicate that precipitation levels varied significantly during the Holocene. After a rapid increase in MAP, a phase of maximum humidity was reached between ca. 11 and 9.6 cal ka BP, followed by a gradual decline in MAP. This trend parallels the reduction in the Northern Hemisphere summer insolation. Comparison of different palaeoclimate proxy records reveal evidence for a stronger Holocene decrease in precipitation in the northern versus the southern parts of the ISM domain. The long-term trend of ISM weakening is overlaid with several short periods of greater dryness, which are broadly synchronous with the North Atlantic cold spells, suggesting reduced amounts of westerly-associated winter precipitation. Compared to the mid and late Holocene, it appears that westerlies had a greater influence on the western parts of the ISM domain during the early Holocene. During this period, the westerly-associated summer precipitation belt was positioned at Mediterranean latitudes and amplified the ISM-derived precipitation. The Tso Moriri pollen record and moisture reconstructions also suggest that changes in climatic conditions affected the ancient Harappan Civilisation, which flourished in the greater Indus Valley from approximately 5.2 to 3 cal ka BP. The prolonged Holocene trend towards aridity, punctuated by an interval of increased dryness (between ca. 4.5 and 4.3 cal ka BP), may have pushed the Mature Harappan urban settlements (between ca. 4.5 and 3.9 cal ka BP) to develop more efficient agricultural practices to deal with the increasingly acute water shortages. The amplified aridity associated with North Atlantic cooling between ca. 4 and 3.6 and around 3.2 cal ka BP further hindered local agriculture, possibly causing the deurbanisation that occurred from ca. 3.9 cal ka BP and eventual collapse of the Harappan Civilisation between ca. 3.5 and 3 cal ka BP.

Influence of the Soil/Solution Ratio, Interaction Time, and Extractant on the Evaluation of Iron Chelate Sorption/Desorption by Soils

Synthetic Fe chelates are the most efficient agricultural practice to control Fe deficiency in crops, EDTA/Fe3+ and o,o-EDDHA/Fe3+ being the most commonly used. Their efficacy as Fe sources and carriers in soils can be severely limited by their retention on it. The aim of this work is to evaluate the possible bias introduced in the studies of the iron chelate retention by soils. For that purpose, results obtained for EDTA and EDDHA iron chelates from two batch studies with different soil/solution ratios were compared with data obtained for a leaching column experiment. Moreover, different extractants were tested to study the o,o-EDDHA/Fe3+ and o,p-EDDHA/Fe3+ desorption from a calcareous soil, and also the effect of the interaction time in their retention process has been evaluated. In summary, the mobility through a calcareous soil of the studied iron chelates differs greatly depending on the type of iron chelate and also on the procedure used to evaluate the retention and the soil/solution ratio used. In general, the leaching column method is preferred because the achieved conclusions are more representative of the natural conditions, but batch methods are very useful as a preliminary experiment, especially one with a high soil/solution ratio. The iron chelate desorption could be quantified by using a sequential extraction with water, sodium sulfate, and DTPA as extractants. Under the experimental conditions used in this study, o,o-EDDHA/Fe3+ retention increased with interaction time.