Two-year Rotation Research Articles

Legumes and cereal crop rotation effect on soil fertility under selected agronomic practices in central farming region, Mongolia

The experimental study aimed at identifying the effects on soil fertility and resources using five different treatments, fallow, non-cultivated land, serial plants, leguminous plants, and grass, was conducted in a central agricultural region of Mongolia. The findings highlight the beneficial effects of cooperative agriculture for food and fodder on the restoration of soil fertility and its resulting useful effect on wheat crop yield. To ensure the stability of soil fertility in the central agricultural region, the key results of the suggest that mobile macro element nitrogen in the soil increased by 45-75.9 per cent over a 3-year rotation with spring soft wheat as the major crop grown along with leguminous plants. Furthermore, the implementation of a two-year rotation of Melilotus albus as intercropping for fodder and food purposes has been found to enhance the rate of soil cellulose decomposition. Furthermore, it has been observed that the continuation of favorable weather conditions and availability of moisture directly correlate with the extent of cellulose decomposition. The aggregate structure of the soil with a diameter of 1-3 mm, which is crucial for growing perennial grass (Agropyron cristatum), is improved by 11.87 per cent to enhance the field's soil structure and reduce erosion. In our research, it was found that legumes have a high protein content and are important role in meeting the needs of livestock and human food, while enriching the soil with nitrogen and increasing the yield of other crops. However, the practical importance of our research lies in the fact that it was established that perennial plants improve the structure of the soil. Legumes, according to our research, are rich in protein and contribute significantly to the provision of food for humans and livestock, as well as to the enhancement of soil nitrogen levels and the growth of other crops. Nevertheless, our study holds practical significance because it proves that grasses enhance the soil's structure as well.

Do rotation and fertilization practices shape weed communities and affect rice yield in low input rainfed agroecosystems in the Malagasy highlands?

Weeds are a major threat in tropical regions where climate conditions favor their growth and development. This is particularly true in low-input rice-based cropping systems in the Malagasy highlands, where weed management is mainly done by manual removal. Crop rotation is often promoted as an efficient way to control weed infestations, while the role of fertilization is more controversial. In this study, we compared rice monoculture to three rainfed rice-based two-year rotations: rice followed by groundnut, rice followed by sorghum-cowpea mixture, and rice followed by a velvet-bean crotalaria mixture. Each rotation was tested with two levels of fertilization (5 t DM ha−1 organic manure, sole or in combination with mineral fertilizer - 400 kg ha−1 NPK + 200 kg ha−1 urea). We assessed the effect of rotation and fertilization on weed composition, diversity, biomass and rice yield. Additionally, the farmers’ perception of weed harmfulness and the relation between their assessment of weed harmfulness and rice production was tested. Our results showed that weed biomass significantly decreased rice yield but only under the low fertilization level. The rotation of rice with the velvet bean-crotalaria mixture was efficient in reducing weed biomass, modified weed community composition and allowed to achieve the highest rice yield. A significant negative relationship was found between weed community harmfulness index and weed species richness. Yet, the lowest rice yield was observed under rice monoculture despite a higher species richness over years and under high fertilization level. The lack of significant correlation between the harmfulness index and the actual rice yield is probably because our index is partly based on farmer’s perception, and only on major weeds. More studies on tropical weed harmfulness are needed to support the design of ecologically intensified cropping systems.

Soil Organic Carbon Dynamics in the Long-Term Field Experiments with Contrasting Crop Rotations

Trends in soil organic carbon (SOC) were analyzed in the soils from the oldest Czech long-term field experiment, the Prague-Ruzyně Long-Term Fertilizer Experiment, conducted on Haplic Luvisol since 1955. The aim of the work was to compare the long-term dynamics of SOC in contrasting crop rotations and different fertilization regimes. The trial design includes two crop rotations (CR): simple CR with two-year rotation of sugar beet and spring wheat, and multi-crop rotation (MCR) with nine crops. Four fertilization treatments were chosen for SOC analysis: unfertilized control, only mineral fertilization (NPK), farmyard manure application (FYM), as well as FYM and NPK application. SOC content was significantly affected by both fertilization and crop rotation practices. In the simple CR, both the unfertilized control and the NPK treatment exhibited a consistent decline in SOC content over the study period, with percentages decreasing from an initial 1.33% in 1955 to 1.15% and 1.14%, respectively. Although the FYM and FYM + NPK treatments showed an increase in SOC content in the 1990s, a gradual decline was recorded in the last two decades. This decrease was not observed in MCR: positive C balances were recorded in all treatments within MCR, with the largest increase in SOC stock occurring when NPK was combined with FYM. In contrast, over the last decade, C balances have decreased in simple CR for all treatments except FYM. This trend coincides with changes in the local climate, particularly rising temperatures. The results indicate that diversified crop rotations and FYM fertilization are effective in mitigating the negative impacts of changing environmental conditions on SOC stocks.

No tillage and leguminous cover crop improve soil quality in a typical rainfed Mediterranean system

Soil and crop management influence soil organic carbon (SOC), chemical composition, and overall soil quality. In a Mediterranean region, a study initiated in 1994 examined the long-term effects of conventional tillage (CT) versus no-tillage (NT) practices. Initially focusing on continuous durum wheat cultivation until 2009, the experiment later introduced a 2-year rotation of durum wheat and Vicia faba L. cover crops in half of the CT and NT fields. SOC was monitored from 2008 to 2018, while microbial biomass (as dsDNA), soluble nitrogen (N), and enzyme activities (EAs) were monitored from 2011 to 2014 to evaluate the rotation’s impact. Between 2009 and 2018, CT yields were on average 15% higher than NT, especially during high rainfall years. NT significantly increased SOC content in the 0–30 cm soil layer, along with higher levels of soluble N, dsDNA, and EAs at 0–10 cm depth. NT led to a 23% and 10% increase in SOC stock and SOC stock per equivalent soil mass compared to CT. EAs increased by over 50% under NT, indicating enhanced biological activity. The SOC increase due to NT was limited to the top 10 cm, with a decrease at deeper depths (up to 50 cm). Introducing cover crops over 4 years did not yield significant impacts, suggesting the need for a longer period to observe noticeable effects. Overall, adopting NT practices resulted in higher SOC concentration, enhanced soil biological activity, and improved biogeochemical cycles, emphasizing the positive impact of NT on soil health and sustainability.

Cover Crop and Crop Rotation Effects on Tissue and Soil Population Dynamics of Macrophomina phaseolina and Yield Under No-Till System.

The effects of crop rotation and winter cover crops on soybean yield and colony-forming (CFU) units of Macrophomina phaseolina, the causal agent of charcoal rot (CR), are poorly understood. A field trial was conducted from 2011 to 2015 to evaluate (i) the impact of crop rotation consisting of soybean (Glycine max [L.] Merr.) following cotton (Gossypium hirsutum L.), soybean following corn (Zea mays L.), and soybean following soybean over a 2-year rotation and its interaction with cover crop and (ii) the impact of different cover crops on a continuous soybean crop over a 5-year period. This trial was conducted in a field with 10 subsequent years of cover crop and rotation treatments. Cover crops consisted of winter wheat (Triticum aestivum L.) and Austrian winter pea (Pisum sativum L. subsp. sativum var. arvense), hairy vetch (Vicia villosa Roth), and a fallow treatment was evaluated with and without poultry litter application (bio-cover). Tissue CFU of M. phaseolina varied significantly between crop rotation treatments: plots where soybean was grown following cotton had significantly greater tissue CFU than plots following soybean. Poultry litter and hairy vetch cover cropping caused increased tissue CFU, though this effect differed by year and crop rotation treatment. Soil CFU in 2015 was substantially lower compared with 2011. However, under some crop rotation sequences, plots in the fallow treatment had significantly greater soil CFU than plots where hairy vetch and wheat was grown as a cover crop. Yield was greater in 2015 compared with 2011. There was a significant interaction of the previous crop in the rotation with year, and greater yield was observed in plots planted following cotton in the rotation in 2015 but not in 2011. The result from the continuous soybean planted over 5 years showed that there were no significant overall effects of any of the cover crop treatments nor was there interaction between cover crop treatment and year on yield. The lack of significant interaction between crop rotation and cover crop and the absence of significant differences between cover crop treatments in continuous soybean planting suggest that cover crop recommendations for midsouthern soybean growers may need to be independent of crop rotation and be based on long-term crop needs.

Effects of Maize-Crop Rotation on Soil Physicochemical Properties, Enzyme Activities, Microbial Biomass and Microbial Community Structure in Southwest China.

Introducing cover crops into maize rotation systems is widely practiced to increase crop productivity and achieve sustainable agricultural development, yet the potential for crop rotational diversity to contribute to environmental benefits in soils remains uncertain. Here, we investigated the effects of different crop rotation patterns on the physicochemical properties, enzyme activities, microbial biomass and microbial communities in soils from field experiments. Crop rotation patterns included (i) pure maize monoculture (CC), (ii) maize-garlic (CG), (iii) maize-rape (CR) and (iv) maize-annual ryegrass for one year (Cir1), two years (Cir2) and three years (Cir3). Our results showed that soil physicochemical properties varied in all rotation patterns, with higher total and available phosphorus concentrations in CG and CR and lower soil organic carbon and total nitrogen concentrations in the maize-ryegrass rotations compared to CC. Specifically, soil fertility was ranked as CG > Cir2 > CR > Cir3 > CC > Cir1. CG decreased enzyme activities but enhanced microbial biomass. Cir2 decreased carbon (C) and nitrogen (N) acquiring enzyme activities and soil microbial C and N concentrations, but increased phosphorus (P) acquiring enzyme activities and microbial biomass P concentrations compared to CC. Soil bacterial and fungal diversity (Shannon index) were lower in CG and Cir2 compared to CC, while the richness (Chao1 index) was lower in CG, CR, Cir1 and Cir2. Most maize rotations notably augmented the relative abundance of soil bacteria, including Chloroflexi, Gemmatimonadetes and Rokubacteria, while not necessarily decreasing the abundance of soil fungi like Basidiomycota, Mortierellomycota and Anthophyta. Redundancy analysis indicated that nitrate-N, ammonium-N and microbial biomass N concentrations had a large impact on soil bacterial communities, whereas nitrate-N and ammonium-N, available P, soil organic C and microbial biomass C concentrations had a greater effect on soil fungal communities. In conclusion, maize rotations with garlic, rape and ryegrass distinctly modify soil properties and microbial compositions. Thus, we advocate for garlic and annual ryegrass as maize cover crops and recommend a two-year rotation for perennial ryegrass in Southwest China.

Challenges and barriers to implementing the WHO Trauma Care Checklist in an emergency department in Nepal: the need for Transformational Leadership

Challenges and barriers to implementing the WHO Trauma Care Checklist in an emergency department in Nepal: the need for Transformational Leadership

Description of the Gap between Local Agricultural Practices and Agroecological Soil Management Tools in Zerhoun and in the Middle Atlas Areas of Morocco

Agroecology is an agricultural, holistic, and innovative approach, which aims to increase the effectiveness, efficiency, and sustainability of agricultural systems. This approach is very rewarding for agriculture in developing countries, mainly in arid zones where water resources are in sharp decline. In this study, we examined farmers’ knowledge by studying existing agricultural production systems and agricultural practices in Moulay Driss Zerhoun (S1) and the Middle Atlas (S2) in central Morocco, to assess the gap between them and the principles and recommendations of agroecology. Data were collected through a survey of 64 farmers, and through field trips and observations. Collected data were analyzed with Chi-square tests and canonical correspondence analysis. Most farms (63.3% in S1 and 52.9% in S2) have an area between 0 and 5 ha. Both areas frequently opt for agroforestry. Olive trees and annual crops (85%), olive trees and fodder crops (10%), and olive trees and market garden crops (5%) are the most recorded associations. Olive trees were used frequently in association with other fruit trees, such as almond trees (15%), carob trees (13%), and fig trees (5%). Of farmers practicing agroforestry, 70% use only organic fertilizers. Thus, 53% of the farmers interviewed at the level of the S2 zone cultivate vegetable crops, against 17% at the level of S1, and only 40% of the farmers of S1 use irrigation, while 60% depend on rainfall. On the other hand, 83.3% of farmers in S1 adopted a two-year rotation—cereals and legumes—against 30% in S2. Tillage or plowing is considered by farmers a necessary procedure before sowing, and, only in S2, 71% of farmers opt for annual tillage of their land for agroforestry. Based on multivariate analysis, the choice of crops was significantly influenced by region and type of organization. However, it was not influenced by topography or farmland size, and the land and area played an important role in the selection of crop types. Raising awareness and introducing agroecological practices in the two study areas based on local knowledge seems essential, with the aim of strengthening the resilience of agroecosystems, respecting the environment, and guaranteeing the sustainability of small farmers through the diversification of their productions. The obtained results from this work are the first in this field of study and constitute a basis for comparative investigations.

Quantification of Internal Medicine Resident Inpatient Care Using the Diagnosis Procedure Combination Database.

Objective Quantification of patient encounters during internal medicine residency training is challenging. At present, there are no established strategies for evaluating the whole inpatient experience in Japan. We hypothesized that the Diagnosis Procedure Combination (DPC) database, which is widely used in Japan, might be a useful tool for such an evaluation. Methods We analyzed DPC-based patient encounters of five senior residents with different types of training. One of the diseases on receipt computation data, including the four main diseases and at most eight comorbidities, was matched with each category in the Online system for Standardized Log of Evaluation and Registration of specialty training system (J-OSLER), and the match ratios were assessed. The accumulation of each disease classified into J-OSLER categories was also assessed. Monthly extra working hours and total patient-days per resident were evaluated using a Pearson correlation analysis. Results Two residents with two-year rotations in the general internal medicine department showed high numbers of patient encounters and the highest matching ratio with J-OSLER (approximately 60% with 4 major diseases, 91% with all diseases). There was a moderately positive correlation between the total patient-days and extra working hours in these residents, but no such correlation was noted in the rate of monthly patient encounters and extra working hours among residents as a whole. Conclusion The DPC-based quantification of patient encounters during residency training appears effective in evaluating the coverage of the current J-OSLER list. Owing to its wide availability and generalization, this matching method may be useful as a universal tool for assessing internal medicine programs.

Annual productivity of cropping sequences: Responses to increased intensification levels

Annual productivity of croplands can be increased by intensifying cropping sequences and fine-tuning agronomic management, improving the ratio between seasonal grain yield and annual available resources. The aims of this study were to evaluate, for different crop sequences and agronomic practices, (i) grain yield (GY), and energy of GY (EY) on annual basis; (ii) the relative contribution of each crop to the annual GY and EY of the crop sequences; and (iii) the maximum attainable annual EY. In a five-year field experiment at the central Rolling Pampa of Argentina, three crop sequences: soybean mono-cropping (Sy), a two-year rotation alternating maize and soybean (Mz-Sy), and a three-year rotation including wheat/soybean, maize, and soybean (Wt/Sy-Mz-Sy) were evaluated under the presence of either fallow (F) or cover crops (CC) during winter, and under two agronomic systems: conventional (CM) and intensified management (IM). For EY, Mz-Sy and Wt/Sy-Mz-Sy sequences greatly surpassed (P < 0.01) Sy (78% and 86% higher) across all years. The CC negatively affected (P < 0.001) the annual GY of the sequences by mostly affecting maize GY (−14% than under F), but this effect varied with the experimental year (rainfall levels) and CC composition (grass/legume proportion). The annual GY of the Mz-Sy (6.47 Mg ha−1) and Wt/Sy-Mz-Sy (6.69 Mg ha−1) sequences increased (P < 0.001) in the IM system compared to CM (5.33 and 5.64 Mg ha−1). In addition, under IM the penalty of CC on the annual GY of the crop sequences was lower (−7%) than under CM (−14%). From the combination of crop sequences and agronomic systems, the highest annual EY corresponded to the more intensified Wt/Sy-Mz-Sy sequence under IM (176 GJ ha−1), doubling the lowest EY obtained by soybean mono-cropping under CM (87 GJ ha−1). This result highlights the opportunity for intensification of cropping sequence and agronomic management to increase the annual productivity of the existing cropping area.

Analysis of cropping pattern in black soil region of Northeast China based on geo-information Tupu.

Different cropping patterns have their own economic and ecological significance. Developing cropping patterns suitable for local conditions is needed to protect and make good use of black soils. At present, the cropping patterns and their spatial characteristics in the black soil region of Northeast China is poorly understood. Based on the crop classification data in 2017-2019, we used geo-information Tupu methods, distribution index model, and bivariate spatial autocorrelation to examine the cropping patterns. The results showed that: 1) The main cropping patterns in the black soil region of Northeast China were continuous maize cropping, continuous rice cropping, continuous soybean cropping, and maize-soybean rotation, accounting for 38.3%, 18.5%, 10.3% and 26.0%, respectively. The maize-soybean rotation included maize-soybean two-year rotation, maize-maize-soybean three-year rotation, and soybean-soybean-maize three-year rotation, accounting for 44.1%, 34.5% and 21.4% of the rotation area, respectively. 2) Various cropping patterns had obviously horizontal differentiation. For instance, continuous maize cropping had very obvious gradient differentiation characteristics in temperature and humidity, but soybean continuous cropping and maize-soybean rotation showed no gradient differentiation, while continuous rice cropping had gradient differentiation only in humidity. 3) Various cropping patterns had obviously spatial clustering characteristics. They had spatial transition characteristics from soybean continuous cropping, soybean-soybean-maize three-year rotation, maize-soybean two-year rotation, maize-maize-soybean three-year rotation, to continuous maize cropping. The cropping pattern in black soil region of Northeast China was dominated by continuous cropping. Understanding its distribution pattern can provide a basis for future spatial optimization of crop rotation.

Reducing carbon footprint without compromising grain security through relaxing cropping rotation system in the North China Plain

The North China Plain (NCP) is an important production base for wheat (Triticum aestivum L.) and maize (Zea mays L.) in China, but intensive continuous winter wheat and summer maize (WM) double-cropping system (control) has also created the high carbon footprint (CF) ecological problems. It is imperative to build a new rotation pattern that not only achieves direct and indirect low greenhouse gases (GHG) emissions, but also takes into account the grain security. CF metrics (per unit area (CFa), per unit economic output (CFe) and per unit kg grain yield (CFy)) were calculated for a two-year crop rotation experiment established at the Wuqiao Experimental Station, from October 2016 to September 2018. The treatments were eight alternative crop sequences grown in the first year, followed by WM in the second year. Alternative crop sequences included (1) WM, (2) fallow, (3) spring maize, (4) winter wheat, (5) spring sweet potato (Dioscorea esculenta (Lour.) Burkill), (6) spring peanut (Arachis hypogaea Linn.), (7) winter wheat-summer peanut, and (8) potato (Solanum tuberosum L.) - silage maize. The results showed that fallow → WM and winter wheat → WM were weak absorption sinks of net GHG, and other rotation patterns were all net sources during the experimental period, while the seven rotation patterns could attain 48%–94% of grain crops yield in control. Spring sweet potato → WM and winter wheat - summer peanut → WM, had no significant differences with control from three different CF perspectives. Spring maize → WM, spring peanut → WM, and potato - silage maize → WM produced more CF than control. Therefore, fallow and planting winter wheat alone in the first year of novel two-year rotation patterns reduced CF in the NCP, planting spring sweet potato and winter wheat-summer peanut increased net income without increasing CF and without compromising grain security, which could attain 1.53 and 1.12 times of the control. The research preliminary showed that winter wheat → WM, spring sweet potato → WM and winter wheat - summer peanut → WM were feasible to trade off of grain production and reducing CF.

Rotating maize reduces the risk and rate of nitrate leaching

There is a strong link between nitrate (NO3-N) leaching from fertilized annual crops and the rate of nitrogen (N) fertilizer input. However, this leaching-fertilizer relationship is poorly understood and the degree to which soil type, weather, and cropping system influence it is largely unknown. We calibrated the Agricultural Production Systems sIMulator process-based cropping system model using 56 site-years of data sourced from eight field studies across six states in the U.S. Midwest that monitored NO3-N leaching from artificial subsurface drainage in two cropping systems: continuous maize and two-year rotation of maize followed by unfertilized soybean (maize-soybean rotation). We then ran a factorial simulation experiment and fit statistical models to the leaching-fertilizer response. A bi-linear model provided the best fit to the relationship between N fertilizer rate (kg ha−1) and NO3-N leaching load (kg ha−1) (from one year of continuous maize or summed over the two-year maize-soybean rotation). We found that the cropping system dictated the slopes and breakpoint (the point at which the leaching rate changes) of the model, but the site and year determined the intercept i.e. the magnitude of the leaching. In both cropping systems, the rate of NO3-N leaching increased at an N fertilizer rate higher than the N rate needed to optimize the leaching load per kg grain produced. Above the model breakpoint, the rate of NO3-N leaching per kg N fertilizer input was 300% greater than the rate below the breakpoint in the two-year maize-soybean rotation and 650% greater in continuous maize. Moreover, the model breakpoint occurred at only 16% above the average agronomic optimum N rate (AONR) in continuous maize, but 66% above the AONR in the maize-soybean rotation. Rotating maize with soybean, therefore, allows for a greater environmental buffer than continuous maize with regard to the impact of overfertilization on NO3-N leaching.

Short-Rotation Willows as a Wastewater Treatment Plant: Biomass Production and the Fate of Macronutrients and Metals

Evapotranspirative willow systems (EWS) are zero-discharge wastewater treatment plants that produce woody biomass and have no discharge to surface or groundwater bodies. The influence of wastewater on the growth of three clones of Salix alba (‘V 093’, ‘V 051’ and ‘V 160’) and the distribution of macronutrients and metals in a pilot EWS receiving primary treated municipal wastewater was studied under a sub-Mediterranean climate. The influent wastewater, shoot number, stem height, and biomass production at coppicing were monitored in two consecutive two-year rotations. Soil properties and the concentrations of macronutrients and metals in soil and woody biomass were analyzed after the first rotation. S. alba clones in EWS produced significantly more woody biomass compared to controls. ‘V 052’ produced the highest biomass yield in both rotations (38–59 t DM ha−1) and had the highest nitrogen and phosphorus uptake (48% and 45%) from wastewater. Nitrogen and phosphorus uptake into the harvestable woody biomass was significantly higher in all clones studied compared to other plant-based wastewater treatment plants, indicating the nutrient recovery potential of EWS. The indigenous white willow clone ‘V 160’ had the lowest biomass yield but absorbed more nutrients from wastewater compared to ‘V 093’. Wastewater composition and load were consistent with the nutrient requirements of the willows; however, an increase in salinity was observed after only two years of operation, which could affect EWS efficiency and nutrient recovery in the long term.

Warming and straw application increased soil respiration during the different growing seasons by changing crop biomass and leaf area index in a winter wheat-soybean rotation cropland

Warming and straw application are two important factors that may influence soil respiration. Investigations of the different effects of warming and straw application on soil respiration during different crop growing seasons are crucial to understand the soil carbon (C) cycles in croplands under future climate scenarios. A two-year field experiment was performed in a winter wheat-soybean cropland in subtropical east China to investigate the different effects of 1.4 °C warming and straw application on soil respiration. There were two main plots, i.e., warming and unwarmed treatments, with three straw application levels: no straw applied, low straw application (6 t ha−1) and high straw application (12 t ha−1) in each treatment. Seasonal variations in soil respiration, soil temperature, soil moisture and leaf area index (LAI) were measured. The results indicated that both warming and straw application significantly increased soil respiration during each growing season. Compared with the unwarmed treatment, warming increased soil respiration by 24.7%, 12.1%, and 12.6% in the plots with no straw applied, low straw application and high straw application, respectively, during the 2017–2019 rotation period. The mean soil respiration during the two-year rotation was significantly (P < 0.01) correlated with root biomass, stem and shoot biomass, grain yield, and LAI. The soil temperature, moisture and LAI-based model accounted for 57.9%-69.1% of the seasonal variation in soil respiration in all treatments. The positive effects of warming and straw application on soil respiration were related more to the variations in crop biomass and LAI than those in grain yield.

Crop yield and economics of cropping systems involving different rotations, tillage, and cover crops

Diversified cropping systems integrated with winter cover crops (CCs) and no-till (NT) systems can provide substantial soil conservation benefits in the midwestern Corn Belt of the United States, but there is uncertainty on how these practices affect producer profits. This study compared crop yield and economic performance from cropping systems that featured three crop rotations: corn (<i>Zea mays</i> L.)–soybean (<i>Glycine max</i> [L.] Merr.; two-year), corn–soybean–oat (<i>Avena sativa</i> L.; three-year), and corn–soybean–oat–winter wheat (<i>Triticum aestivum</i> L.; four-year); two tillage systems: NT and conventional-till (CT); and two cover cropping managements: CC and no-cover crop. Tillage and rotation treatments were established in 1991 whereas cover cropping was introduced in 2013, so data from 2014 through 2018 were used for the yield and economic comparisons. Over the study period, the NT system reduced the corn yield across all rotations but increased the soybean yield under two-year rotation as compared to the CT system. Hence, both tillage systems were economically equivalent, whereby the NT system improved benefit-cost ratio as compared to the CT system. In our study, while CC in its short term did not contribute to yield and overall economic benefits, we observed highest gross revenue and second-best net returns from two-year CC plots under the NT system as compared to all other cropping systems. When compared to two-year rotations, diverse crop rotations (three- and four-year) increased the corn and soybean yields and associated profits yet compromised overall profitability due to the lower profits of small grains. It is important to identify other profitable crops that are beneficial for soils and the environment to diversify the corn–soybean rotations.

Effect of Crop Rotations and Continuous Fertilization on the Status of Silicon (Si) Available in Soil in a 97-Year Permanent Experiment

ABSTRACT This work aims to study the status of silicon (Si) as a plant nutrient in the soil of Bahtim long-term field experiment in Egypt under the effect of crop rotations system and continuous fertilization. The experiment has been set up since 1912 based on two main factors: (1) crop rotations: mono-cropping (MC), two-year rotation (2Y-R), and three-year rotation (3Y-R), and (2) Fertilization: mineral nitrogen N, phosphorus P, potassium K, and organic farmyard manure FYM. Available N, P, K, and Si in soil were estimated. Productivity of soil was evaluated using Berseem (Trifolium alexndrinum L.) cultivated and harvested in 2019. The plant-available Si (PAS) in soil decreased significantly compared to the control C in case of MC by 70.26%, 2Y-R by 85.09%, and 3Y-R by 92.65% in the direction of N > NP > NPK. Mineral fertilization decreased the PAS significantly by 12.84% N, 29.52% NP, 78.45% NPK compared to the control C in the order of MC > 2Y-R > 3Y-R. Berseem yield (t ha−1) increased significantly compared with the control C following the order C < N < NP < NPK. The most significant increase in the yield was recorded for the NPK treatments by 224.04%, and 200% in case of MC, 2Y-R, 3Y-R, respectively.

Bioactive Properties of Fruits and Leafy Vegetables Managed with Integrated, Organic, and Organic No-Tillage Practices in the Mediterranean Area: A Two-Year Rotation Experiment

The sustainability of current farming systems has been questioned in the last decades, especially in terms of the environmental impact and mitigation of global warming. Also, the organic sector, which is supposed to impact less on the environment than other more intensive systems, is looking for innovative solutions to improve its environmental sustainability. Promisingly, the integration of organic management practices with conservation agriculture techniques may help to increase environmental sustainability of food production. However, little is known about the possible impact of conservation agriculture on the content of bioactive compounds in cash crops. For this reason, a two-year rotation experiment used 7 cash crops (4 leafy vegetables and 3 fruit crops) to compare integrated (INT), organic farming (ORG), and organic no-tillage (ORG+) systems to evaluate the possible influence of cropping systems on the nutritional/nutraceutical values of the obtained fruits and leafy vegetables. The results pointed out specific responses based on the species as well as the year of cultivation. However, cultivation with the ORG+ cropping system resulted in effective obtainment of fruits and vegetables with higher levels of bioactive compounds in several cases (11 out 16 observations). The ORG+ cropping system results are particularly promising for leafy vegetable cultivation, especially when ORG+ is carried out on a multi-year basis. Aware that the obtained data should be consolidated with longer-term experiments, we conclude that this dataset may represent a good starting point to support conservation agriculture systems as a possible sustainable strategy to obtain products with higher levels of bioactive compounds.

A suitable rotational conservation tillage system ameliorates soil physical properties and wheat yield: An 11-year in-situ study in a semi-arid agroecosystem

With the changing global climate, dryland agriculture faces major challenges related to soil water scarcity and soil erosion, threatening global food safety and sustainability. Conservation tillage rotation is considered to be an effective method that can better alleviate these threats if the plowing method is retained and incorporated into the popular no-tillage and subsoiling rotation systems. With this in mind, a long-term (2007–2018), plowing-based conservation rotational tillage experiment was established in an extraordinarily semi-arid region in Heyang Country, Shaanxi Province, China. Four treatments were applied: (1) a three-year rotation where the first year was no-tillage, the second year rotated via alternate plowing, and the third year was subsoiling tillage (NPS); (2) a two-year rotation alternating annual subsoiling tillage with plowing (SP); (3) a two-year rotation alternating annual plowing tillage with no-tillage (PN); and (4) continuous annual plowing (P). After the 11-year experiment, three rotational systems (NPS, SP, and PN) had significantly ameliorated soil bulk density (BD), porosity, and water-stable aggregates (WSA). Especially when compared to the P treatment, the SP rotation significantly reduced mean BD (5.19 %) and increased porosity (5.69 %) at 0–60 cm soil depth. This happened with higher amounts of water-stable macro-aggregates (26.92 %), and may have a synergetic relationship between the WSA of 2–5 and 0.25–2 mm at 30–40 cm soil depth. Also this significantly enhanced the average soil water storage (0–200 cm) under wet rainfall patterns (500.50 mm), and even occurred in extremely dry (391.37 mm) and wet (566.26 mm) years; as well significantly promoted the average water use efficiency (7.25 %) and yield (8.37 %), respectively. Overall, the SP rotation is a suitable agricultural tillage scenario for ameliorating soil bulk density, porosity, water-stable aggregates, water use and storage, yields, and profits that meet the variable climate of dryland farming ecosystem in the future.

Analysis of cropping patterns in Sudan's Gash Spate Irrigation System using Landsat 8 images

Spate irrigation has been conducted in eastern Sudan's Gash Delta; however, availability of data necessary to understand actual conditions is limited. Therefore, we identified annual land cover types (irrigated crop land, non-crop land, and shrub land) in the Gash spate irrigation system using images obtained from Landsat 8. Further, we analyzed spatial cropping patterns and crop-fallow rotation characteristics for six irrigation blocks (Kassala, Mekali, Degain, Tendelai, Metateib, and Hadaliya) based on land-cover classification. To classify land cover types, we compared three vegetation indices, including the normalized difference vegetation index (NDVI), and examined six water-related indices, including the normalized difference water index (NDWI). Comparing the accuracy of these indices shows that NDVI and NDWIGS1 calculated from green and short-wave infrared performs best for land cover classification. We identified irrigated areas with a decision tree model using NDVI and NDWIGS1 time series data. The results showed that irrigated areas vary annually and are determined by available water resources from the Gash River. We found that the coefficient of variation of the irrigated areas is lower in the upper irrigation blocks (Kassala and Mekali) and higher in the lower irrigation blocks. We investigated crop-fallow rotation patterns and show that a two-year rotation pattern, in which irrigation and fallowing are conducted alternately, is dominant in the two upper irrigation blocks (Kassala and Mekali), while a three-year rotation pattern in which land lies fallow for two years is the main type adopted in the two lower irrigation blocks (Metateib and Hadaliya).