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The advancement of technology has been influenced and enhances the production rate and quality of industrial and agricultural products. This study aimed to design and manufacture portable and multiple seed planting machines from locally available materials. The paper deals principally with the design and manufacturing process of the seeder machine. The design feature considers the geometrical components, driving power determination, and stress and forces Analysis of each part. Pro-Engineer and solid work software were used for part details and assembly drawing. Materials were selected based on functionality, durability, cost, and local availability. Hence, Sheet metal steel was used for the fabrication of the seed and fertilized boxes, seed, and fertilizer metering disc were fabricated from polyvinylchloride (PVC) and the power transitions elements like transitions shafts and gears also fabricated from round steel bar. The seeder machine was assembled by the permanent joining of the frame (Arc welding), and the remaining components were bolted to each other in their places. Experimental tests have been performed to evaluate the performance and functionality of the seeder. It was observed that the machine had been put (dropped) the seed within the design space gap between the consecutive plants and the required amount of fertilizer were placed with the designed depth.

Agricultural open burning, i.e., the practice of burning crop residue in harvested fields to prepare land for sowing a new crop, is well-recognized as a significant contributor to CO2 and black-carbon emissions, and long-term climate change. Low-soil-tillage practices using a specific agricultural machine called Happy Seeder, which can sow the new seed without removing the previous crop residue, have emerged as the most effective and profitable alternative to open burning. However, given the limited number of Happy Seeders that the government can supply, and the fact that farmers incur a significant yield loss if they delay sowing the new crop, farmers are often unwilling to wait to be processed by the Happy Seeder and, instead, decide to burn their crop residue. We study how the government can use effective information-disclosure policies in the operation of Happy Seeders to minimize agricultural open burning. A Happy Seeder is assigned to process a group of farms in an arbitrary order. The government knows, but does not necessarily disclose, the schedule for the Happy Seeder at the start of the sowing season. Farmers incur a disutility per unit of time while waiting for the Happy Seeder due to the yield loss as a result of late sowing of the new crop. If the Happy Seeder processes a farm, then the farmer gains a positive utility. At the beginning of each period, each farmer decides whether to burn her crop residue or to wait, given the information provided by the government about the Happy Seeder's schedule. We propose a class of information-disclosure policies, which we refer to as dilatory policies, that provide no information to the farmers about the schedule until a pre-specified period and then reveal the entire schedule. By obtaining the unique symmetric Markov perfect equilibrium under any dilatory policy, we show that the use of an optimal dilatory policy can significantly lower the number of farms burnt compared to that under the full-disclosure and the no-disclosure policies. Using data from the rice-wheat crop system in northwestern India -- an area of the world with the highest prevalence of open burning -- we conduct a comprehensive case study and demonstrate that the optimal dilatory policy can reduce CO2 and black-carbon emissions by at least 14%.

Precision Rice Seeding System (PRSS) is a system of planting rice with the use of a precision rice seeder (PRS). The PRSS was initially introduced to rice farmers in Cagayan Valley Region, Philippines. This study was conducted to assess the determinants of the level of awareness, acceptance, and utilization of PRSS and the benefits of its utilization. The respondents in this study were the farmer-users and farmer-non-users. All data were gathered through the use of an interview schedule. Data were analyzed using correlations, linear, and logistic regression. Cost and return analysis and partial budgeting were used to determine the financial benefits of using the PRSS. Results revealed that attendance to promotional activities was a significant predictor of the higher level of awareness and acceptance of the PRSS among farmer-users (p

To maintain good continuous working performance in a vacuum plate seeder, it is important to monitor the distribution of seeds in real time and automatically adjust vibration parameters accordingly. Seed motion in a rectangular vibrating tray with vibration varying with time and interference by direction angle was simulated using the discrete element method (DEM). A plane model P was used to describe the variation of seed layer thickness. Four square areas on the bottom of the tray were divided symmetrically near the four corners to measure seed layer thickness, and a monitoring plane model Pm was established. DEM simulation results showed that the models Pm and P had the similar change rules, although there were some differences in fitting parameters. There was obvious time delay in the change of Pm compared with P. Therefore, a grey system model (GM) was adopted to predict the change of Pm, and two back-propagation (BP) neural networks which take GM prediction results as input parameters were developed respectively. Then, according to the BP neural networks outputs, a prediction plane model Pp was proposed to predict the seed distribution. Experiments were carried out on a test-rig to validate these predictions. The seed distribution plane P was measured manually, the monitoring plane Pm was established using seed layer thickness measurement results and the prediction plane Pp was established using the GM and BP neural networks. The results indicated that the proposed method had good precision and stability and provides the basis for the design of an automatic control system for the vibrating tray to promote a uniform seed distribution.

No-till seeding requires a seeder that can effectively cope with the untilled soil and place the seeds at an optimum depth in order to achieve a reliable germination and rapid plant emergence. This aim is more challenging due to the inappropriate response of the machine dynamics to harsh soil conditions, such as the compacted soil undulations and the presence of the stubble. In this paper, a seeder main frame carrying a seed dose mechanism and two no-till seeding assemblies was developed and designed with multiple sensors, to capture the dynamics of the assemblies together with the corresponding surface profile. A magnetorheological (MR) damper was implemented into one of the seeding assemblies to optimise its dynamics for better seed placement. A number of strain gauges were used to measure the dynamics of the seeding assemblies, like vertical and impact forces during seeding operation at a travelling speed of 10 km h−1. The accuracy of the surface profile sensing system was validated by obtaining the profile of trapezoidal bumps with georeferenced dimensions resulting in a root mean squared error of 9.6 mm and 9.9 mm for the damped and undamped seeding assembly, respectively. Experiments were performed seeding wheat (Triticum aestivum L.) operation with a target depth of 40 mm with different damping parameters set on the MR damper by feeding its coil with different current values. The position of each single seed within nine 2 m sections was georeferenced using a total station, to calculate the seeding depth for both seeding assemblies. The seeding assembly with the MR damper, excited with 0.5 A, resulted in a better seeding depth variation with a mean value of 39.8 mm, standard deviation of 5.8 mm and 95th percentile of 49.8 mm over that of other current values applied on the MR damped and the original seeding assembly. The dynamics were improved with a reduction of 21.34% and 67.69% in the amplitude of the vertical and impact forces, respectively. The seeding depth error compared to the target depth for the damped seeding assembly (at 0.5 A) was less than 11.9 mm for 95% of the samples, while this figure was equal to 21.3 mm for the undamped seeding assembly.

In order to improve the mechanical performance and automation of the planter’s fertilization device, this article uses the TRIZ theory for innovative design and guidance. It uses two screens, function analysis and two TRIZ tools to complete the design of the model, structure model and function model. Analyze many contradictory issues such as technical contradiction analysis and material field analysis to solve many problems. Finally, through the rational design of the electronically controlled part and the mechanical device structure, nitrogen, phosphorus, and potassium are automatically mixed and fertilized. It improves the utilization of nitrogen in China and avoids the waste of fertilizer, has high control precision, high reliability, saves costs, increases productivity, and achieves precision agriculture. Lay a good foundation for the realization of the modernization of agriculture.

With the development of agricultural intelligence, the degree of integration of computer technology, wireless communication technology, sensor technology, and agricultural machinery technology is getting higher and higher. Among them, the seeding parameter monitoring technology of the seeder has been more and more applied. However, the current seeding monitoring technology still has some problems, including the low accuracy of parameter monitoring, the monitoring parameters are mainly the seeding quantity, the data is communicated by wire connection, the communication distance is short, the wiring is complicated, and the scalability is poor. Aiming at the problems existing in the current seeding parameter monitoring technology, this study designed and developed a precision seeding parameter monitoring system based on laser sensors and wireless serial port communication for precision seeders. The monitoring system included the design of laser sensor, the design of controller parameter capture and calculation, the design of upper computer human–computer interaction software, the design of wireless communication methods, the design of fault alarm, and speed measurement function. Bench tests had shown that the monitoring system designed in this study had high monitoring accuracy. When the simulated seeder was at a forward speed of 5–10 km/h, the average monitoring error of the seeding quantity was less than 1.2%, and the average monitoring error of the seeding qualified rate was less than 0.5%. The monitoring system could accurately and timely alarm the fault, which the success rate of alarm reached 100%, and the average response time of the fault alarm was less than 0.5 s. The GPS speed measurement value was consistent with the simulation software value, and the speed measurement frequency was 5 Hz. Field tests had shown that the average monitoring error of the seeding quantity was less than 1%, and the average monitoring error of the seeding qualified rate was less than 1.5%. The monitoring system could alarm in time when the seeder had a missing seeds fault. Through test verification, the monitoring system designed in this study could realize the online real-time monitoring function of the precision seeder.

Manual supplemental seeding in plug seedling production is a labor intensive and very tedious task. This paper studied and developed an automatic supplemental seeding device using machine vision technique for corrections of seeding errors of plug seeder, and replacement of the manual reseeding. The device includes five units: sweet corn seed detection, seed releasing, seed picking up, and plug tray conveying. A voting mechanism-based sweet corn seed detection method was proposed for detecting the missing seeds in a moving plug tray. The seed releasing cells and the suction nozzle for picking a seed up were fabricated using 3D printing technique. The proposed device was placed into the practical growing seedling pipeline to test its reseeding performance. The results showed that the sweet corn seed detection accuracy was about 99%, the empty cell rate decreased from 9.61% to 0.38% (after reseeding) on average, and the reseeding rate was about 221 trays per hour when the miss-seeding rate was under 5%. This proved that the proposed supplemental seeding device has great significance for increasing the seeding precision of sweet corn, and improving the efficiency of the practical seedling.

Rice residue management (RRM) impacts ecosystems’ sustainability due to change in energy use, C footprints (CFs) and net ecosystem C budget (NECB). The energy input-output and CFs were audited to optimize energy use and C equivalent emissions (CE) in wheat following RRM with Happy Seeder using data collected from 53 farmers during face-to-face interview. Average total energy input (EI) of 23.5 GJ ha−1 produced output energy of 204.8 ± 2.9 GJ ha−1, with energy productivity (EP) of 0.24 kg MJ−1. The net energy gain (NEG) of 181.3 ± 3.0 GJ ha−1 was achieved with energy use efficiency (ER) of 8.81 ± 0.19. Chemical fertilizers were the major hotspots of energy (∼48.4% of EI) and CFs (∼59.2% of CE) in wheat cultivation. Data Envelopment Analysis (DEA) elucidated 23 decision making units (∼43% of total) as energy efficient, whilst 30 as inefficient with average technical efficiency (TE), pure technical efficiency (PTE) and scale efficiency (SE) were 0.94, 0.97 and 0.94, respectively. DEA helped energy saving of 1462.8 MJ ha−1 (∼6.2%), mitigation of 107.8 kg CO2e ha−1 (∼7.6%) with significantly higher NECB of 716.4 kg C ha−1 (∼19.1%) due to change in soil organic C (ΔSOC) pool by 34.8 kg C ha−1 at efficient Happy Seeder sown wheat farms.

Based on Droplet Measurement Technologies data of a pre-stratiform-cloud precipitation event in Ganzhou, Jiangxi Province, on 11 November 2015, and combined with radar data, this paper comprehensively analyzes the macro- and microphysical characteristics of cloud in the upper trough. The results show that: (1) Detection takes place in the early stage of precipitation and the cloud has multiple layers. The cloud type is stratiform (Sc) and the height of the cloud base is 1009 m, 1009–1700 m is the low Sc layer, 1700–3000 m is the no-cloud level, and 3000 to the maximum height detected is another Sc layer. (2) The Sc is inhomogeneous in the horizontal and vertical directions. The particle number concentration and the effective diameter below the 0 °C layer is significantly higher than that above the 0 °C layer, which is in accordance with the ‘seeder–feeder’ mechanism. Above the 0 °C layer is seeder cloud, where needle, column ice crystals and water droplets coexist, and sublimation and coalescence are the main processes. The morphology of ice crystals changes from needle to column, plate, and polymer as height decreases. Below the 0 °C warm layer is a supply cloud, and the particles develop in the supply cloud with abundant liquid water content. Ice melting and coalescence dominate the warm layer, which makes the effective diameter significantly increase. Down to 4150 m, the ice melts completely into raindrops.

Despite Erica being the most diverse genus in the Cape Floristic Region, very few studies have focused on their breeding systems. The ability to self-fertilise autonomously and to tolerate self-pollen was assessed in three bird-pollinated obligate seeder ( E. densifolia , E. sessiliflora and E. discolor ) and three insect-pollinated obligate seeder ( E. penicilliformis , E. scabriscula and E. formosa ) Erica species in the southern coastal part of the Cape Floristic Region. None of the species successfully reproduced through autogamy and only the bird-pollinated E. sessiliflora produced a significant proportion of viable seeds per fruit when selfed. With the other five Erica species examined, cross-pollination yielded a significantly higher proportion of viable seeds per fruit compared to other treatments (autogamy and self-pollination). This suggests that the role of pollinators is essential for the reproductive success of Erica regardless of their pollination system (bird- versus insect-pollination) and that most are out-crossers.

Identification of a suitable cultivation method with low energy use, GWP and high productivity is the need of the hour. A 16-year old field study in the Indo-Gangetic Plains (IGP) with different methods of rice cultivation viz., zero tillage (ZT), happy turbo seeder (HTS), bed planting (BP), reduced tillage (RT), conventional sowing (CS), direct sowing (DS), broadcast method of sowing (BS), manual transplanting (HT) and selected transplanting methods like, manual transplanter (MT) and mechanical transplanter (MaT) was used to evaluate the energy input and GWP. HT method of rice cultivation recorded higher energy use than ZT, HTS, BP, RT, CS, DS and BS methods, respectively. Whereas HTS method recorded highest net grain energy (NEg) and this was followed by ZT and MaT, The PTR method recorded 61–66% higher GWP compared with direct sown unpuddled method of rice cultivation. Among direct sown unpuddled methods of rice cultivation, HTS, BP, RT and ZT had lower GWP than farmers' practice. MaT recorded higher carbon output than ZT, HTS, BP, RT, CS, DS and BS methods. The study indicated that direct seeded method of rice cultivation is energy efficient with lower GWP and thus may be recommended.

Precise seeding depth plays an important role in achieving reliable germination rate and even plant emergence. In no-till seeding, this aim is more challenging due to the inappropriate response of the machine dynamics to harsh soil conditions, such as compacted soil undulations and stubble. In this paper, a sensor-frame was mounted on a no-till seeder, to measure the field surface profiles during seeding operation. Its accuracy was validated by acquiring the profile of trapezoidal bumps with known dimensions resulting in a root mean squared (RMS) error of 7.3 and 8.7 mm for travelling speed of 2 km h−1 and 10 km h−1, respectively. Strain gauges were used to measure the soil reaction forces, on one of the seeding assemblies during seeding operation at travelling speed of 10 km h−1. After seeding wheat (Triticum aestivum L.), the geo-referenced position of each single seed was measured using a total station, to calculate the seeding depth. The correlation between the seeding depth variation and the developed forces showed that the frequencies of 11.8 Hz and 17.8 Hz of the vertical forces, which corresponded to a wavelength of 0.21 m and 0.14 m, respectively, were responsible for the high variation in seeding depth. For the profile impact forces, these values were equal to 10.7 Hz and 20.6 Hz. The corresponding wavelengths were equal to 0.23 m and 0.12 m. The peak value of seeding depth was detected at a frequency of 8.3 Hz with 0.3 m wavelength for both vertical and impact profile forces.

In no-till seeding, one of the biggest challenges to achieve a reliable seed germination and an even plant field emergence is an extreme variation in the desired seeding depth. This is caused by the inadequate response of the seeder motion dynamics to harsh soil conditions and to high operating speeds. In order to assess and optimise the dynamic response of a no-till seeder, mathematical models were developed for simulating the vertical motion of a coulter assembly. The models included the dynamics of the coulter assembly, with the packer wheel as a passive system, and a semi-active MR (magnetorheological) damper system, which was considered to be located in-between the coulter and the packer wheel. The developed model of the coulter assembly dynamics was validated based on a correlation between the simulated and the measured impact forces and pitch angles. A root-mean-squared (RMS) error resulted from the correlation have increased from 6.84% at the lower speed of 10 km h −1 to 14.5% at the higher speed of 15 km h −1 for the impact forces, from 8.1% at the lower speed of 10 km h −1 to 13.1% at the higher speed of 15 km h −1 for the pitch angle. Conversely, there was a fall in the correlation coefficient from 0.699 to 0.681 for the impact forces and from 0.942 to 0.684 for the pitch angle between the lower speed of 10 km h −1 and the higher speed of 15 km h −1 , respectively. Furthermore, all three applied hysteresis models, such as Bingham, Dahl and Bounc-Wen model, for the semi-active MR damper system behaviour demonstrated significant improvements over the passive system model. Among the models, the Bouc-Wen model produced more adequacy of the MR damper behaviour with the highest reduction of 54.1%, 63.3% and 41.2% in the amplitude of the impact forces and 52.3%, 58.2% and 38.1% in the amplitude of the pitch angles at the speeds of 10 km h −1 , 12 km h −1 and 15 km h −1 , respectively.

The agricultural sector is facing increasing societal expectations to contribute to the global reduction of impacts on the environment. This study aims to evaluate energy use and environmental impacts of different winter wheat tillage systems in the central Fars province, Southwest Iran. To meet the objectives, different energy indices and environmental impact categories were assessed for five wheat tillage systems; two conventional tillage systems: CT1 and CT2 , and three conservation tillage systems: CMT (moldboard plough and combined seeder), RDT (reduced tillage) and NT (no-tillage). Total average energy consumption was estimated at 30,000 MJ/ha caused mainly by fertilizers, diesel fuel, water and seed inputs. The highest output-input energy ratio and energy productivity were observed in the conservation tillage systems RDT followed by NT and CMT . The LCA analysis confirmed that system RDT is the wheat tillage system in the region with the lowest impacts on the environment, the lowest energy input and the highest benefit to cost ratio compared to all other considered systems.

To improve the operating efficiency of seeders and enable the seeder-metering device to keep good metering performance at different operating speeds of seeders, in this paper a multifunctional smart test bench for STB-700 seeder-metering devices and a 2BJYM-5 maize-soybean interplanting precision seeder, were used for metering and seeding tests with two different kinds of soybean and maize seeds. Research results showed that, the rotating speed of the seeder-metering device at different operating speeds of maize-soybean interplanting precision seeders had influence on the metering performance of the seeder-metering device. Then the influence trend was explored. With the function fminbnd in MATLAB, the minimum point of acceptable re-seeding rate was determined to be at 43.05 r/min, the minimum point of miss-seeding rate at 39.96 r/min and the minimum point of interplanting distance variation coefficient at 40.25 r/min. Therefore, the optimal operating speed range of the seeder-metering device when being installed in the seeder was identified, further determining spoon-shaped metering devices and adjustable cell-wheel metering devices not suitable for seeding at high speeds.

Managing production risks under high rainfall variability remains a research priority in Southern Africa. In this region, conservation agriculture (CA) has been promoted as useful set of principles that could improve farmers' resilience to climate variability and change. However, matching practices to agro-ecological and farmers' socio-economic conditions remain contentious. Here we combine empirical data and results from a cropping system model to quantify benefits and trade-offs, in terms of sowing opportunity, yield, and yield variability, from adopting CA practices. We hypothesized that CA practices would require less labour, allow farmers to plant earlier, at times closer to optimum planting times and consequently result in higher maize yields. We tested the hypothesis using available household labour and the outputs from a cropping systems model (DSSAT) run for six locations in Malawi, Mozambique and Zimbabwe. Thirty years of climate records and soil characterisations were available for each site. Modelled CA practices included, a basin planting system prepared early during winter (CA-Basins early); a basin planting system prepared late and at the onset of the rains (CA-basins late); an animal draught direct seeder e.g. using a Fitarelli animal traction planter (CA-Direct seed); an animal traction ripper (CA-Ripper); and a dibble stick manual planting system (CA-Dibble). Check conventional cropping systems included conventional mouldboard ploughing prepared early (CMP-early), and late (CMP-late), which mimicked farmers having early or late access to draft power, respectively. Simulated results showed that CA-Ripper, CA-Direct seeding and CA-Basins improved timeliness of operations and enabled earlier planting across all locations compared to conventional systems. Mechanized CA systems potentially offered farmers flexibility on when to plant. However, timely planting of CA systems did not translate into higher yields when carried out during periods of high rainfall variability. Yield benefits of early plantings in CA were only apparent in Zimbabwe. Rainfall patterns showed a shift of 0.28 and 0.39 days yr− 1 in planting dates at Chitala and Chitedze, over the simulated 30 years. However, this was not evident at the other four locations. Optimum planting dates established for the six locations were 5th to 27th December for Malawi; 26th December to 7th January for Mozambique; and 4th to 7th December for Zimbabwe. For each location, planting maize close to the optimum period resulted in higher yields, irrespective of cropping system. Significantly (P

This paper presents a ditch device which is suitable for being used in rainy area. It can effectively reduce field work frequency by installing such device on a seeder. Through conducting ANSYS-based modal analysis for such ditch device, we obtained the natural vibration frequency and response effect of the ditch device (during field working, the vibration frequency of the ditch device was 8-9HZ). The natural frequency of ditch device completely avoided the machine vibration frequency in seeding period, and thus avoided poor working conditions caused by resonance. Harmonic response analysis was also performed on the basis of modal analysis. Results showed that the ditch device was subjected to very small stress and deformation displacement when the machine was in vibration condition, which will not affect the strength and stability of ditch device.

One of the significant obstacles in achieving a reliable seed germination and even plant field emergence in no-till seeding is a variation in the desired seeding depth. This is caused by the inappropriate response of the seeder motion dynamics to harsh soil conditions and to high operating speed. In order to assess the dynamic response of a no-till seeder, a mathematical model, which simulated the vertical motion of a seeding aggregate, was developed. A correlation between the simulated and the measured parameters resulted in a root-mean-squared (RMS) error of 17.2% and 6.4% for impact force and pitch angle, respectively. The simulated impact force frequencies of interests were detected at the critical frequencies of the measured forces with high coherence values.

The main objective of the project is development and fabrication of a multipurpose agricultural tiller which will perform a wide range of operations such as rotary, ploughing, seeding, pesticide spraying, harvesting, weeding at a reasonable cost to overcome the challenges faced by the farmer. The multipurpose agricultural tiller has been fabricated on a rigid chassis frame which holds a universal shaft on which rotary and wheels can be mounted. This universal shaft derives 8 BHP of power from a 4-Stroke IC engine placed firmly on the chassis frame. The mechanism used is such that the same engine drives the wheels, rotavator, harvester, pesticide sprayer, seeder, leaver, plough and trolley. The reciprocating motion provided to the harvester cuts the crop precisely, consuming less time as compared to conventional techniques of harvesting. A power sprayer is used which will facilitate spraying of pesticide at different heights of crop cultivation. A multi-way adjustable plough is also used whose position can be adjusted on a slide through frame according to the requirement of the farmer. A multi variety seeding operation is also setup. Multipurpose agricultural tiller can be easily afforded by average and marginal class of farmers.

Automated sowing performance monitoring for pneumatic roller-type vegetable plug-tray seeders helps reduce labor and ensure high sowing quality. In this study, a row of optical fiber sensors was utilized, and an optoelectronic measurement system was constructed based on the row-by-row sowing principle of the seeder. Performance of the measurement system was evaluated by sowing ten types of vegetable seeds. The results demonstrated there were no significant differences in measurement accuracy at different sowing speeds. Further, the seed properties did not influence the missed-seeding consistency ratio (CRms). The average CRms of the developed system was 99.81%. Seed shape was an important factor that influenced the single-seeding (CRss) and multiple-seeding (CRmu) consistency ratios. Seeds with greater than 85% sphericity obtained an average CRss and CRmu of greater than 99%, which demonstrated that the developed measurement system could be applied to vegetable plug-tray sowing.

Reproductive output and seed traits can be altered by water availability during seed formation and maturation, which could affect the population recovery after fire of seeders (i.e., species regenerating from seeds). This is important for species in fire-prone, dry areas that are projected to encounter reduced total precipitation and longer annual drought with climate change. Here we determine the sensitivity of several reproductive processes to drought in Cistus ladanifer , a plant widely distributed in the shrublands of the western part of the Mediterranean Basin. Three levels of annual drought were simulated in a shrubland by means of a rainout shelter and an irrigation system in 6 × 6 m plots. Fruits and seeds from drought-exposed mother plants were collected, and reproductive output, seed size and anatomy studied. Seeds non-exposed/exposed to fire cues (heat plus smoke) were germinated at five levels of water stress (Ψ s = 0.0 to −0.50 MPa). Hydrotime modeling was applied to germination under water stress. Plant growth was sensitive to drought, but reproductive output, seed size, dormancy and viability were not. Drought significantly affected seed anatomy, increasing the palisade layer at the micropyle. Drought in the maternal plants, in interaction with seed exposure to fire cues, significantly reduced final germination. Water stress during germination decreased final germination, independent of maternal plant drought, and interacted with fire cues to decrease germination when exposed. Hydrotime modeling confirmed that fire cues made seeds highly sensitive to water stress (Ψ b (50) = −0.25 MPa). Post-germination viability was reduced in seeds from drought-treated maternal plants that were exposed to fire cues and germinated under water stress. Reproductive output showed low plasticity in response to drought. However, the effects of drought in the mother plant affected seed anatomy and germination in interaction with fire cues. The conclusion is that exposing C . ladanifer maternal plants to drought arguably increases seed sensitivity to water limitations during germination after fire.

The distribution limits of species are mainly related to climate but other environmental factors such as soil and fire may also play an important role in local population dynamics. Species that re-establish from seed after a severe disturbance (seeder species) should have different functional attributes from species that can survive a disturbance by vegetative regeneration (resprouters). The functional attributes will influence the establishment and survival of individuals and for trees, the stem size distributions provide a view of the history of the populations and may indicate the trajectories of the populations as they age. Two congeneric tree species – Allocasuarina fraseriana (a resprouter) and A. huegeliana (a seeder) are dominant to subdominant trees in forest and woodland vegetation of south western Australia and illustrate useful comparisons of functional attributes and population structures. Both species occupy fire prone vegetation, bear seeds in serotinous cones and are considered to regenerate new individuals after fire events. The seeder (Allocasuarina huegeliana) has smaller cones and seeds and more seeds cone-1 than the resprouter (A. fraseriana). The cones of the resprouter provide more protection against heat to the contained seeds than the seeder. It is generally considered that species in fire prone environments often rely on disturbance to provide suitable conditions for regeneration and recruitment between disturbances is poor. For a species killed by disturbance population structures years after the disturbance would be expected to be unimodal while a resprouter would have a multimodal structure, as adults would survive and remain in the population with the new recruits. Unexpectedly population structures for the two species we studied were very similar when compared at an overall landscape scale. We attribute this mainly to the ability of the species to recruit interfire. Best seedling recruitment does occur after fire, as this provides an environment with more nutrients and reduced competition for the seedlings. However interfire recruitment can be abundant in some habitats. The degree to which this occurs may vary in relation to co-occurring tree species and landscape position. In general, fuel reduction fires are being used to reduce the danger of high intensity fires as the climate becomes drier and hotter in parts of southern Australia and mild fires will influence recruitment of both species. Low intensity surface fires will remove interfire recruits of the seeder species, but may increase the density of small plants of the resprouter. Adults are unlikely to be damaged but size class structures will be different from those after stand replacing fires.

In order to solve the problem of poor uniformity and low depth stability in traditional tube seeding (TTS), this paper proposes a no-tube seeding (NTS) method for wheat sowing. A NTS test platform was constructed, and accuracy and uniformity of seeding quality were optimized with the ground clearance as the experimental factor. It was found that the ground clearance with the seeding accuracy and uniformity were both quadratic functions. The seeding quality was good in ground clearance range of 5∼8.8 cm, and ground clearance of 7 cm was in line with the actual seeding conditions, the corresponding seeding accuracy was 83.84 % and the variation coefficient of seeding uniformity was 14.68 %. The NTS machine was designed and grooving scheme for seeding was optimized by adopting a convex plate on the cylindrical surface of press wheel. The depth and width stability of the grooving operation was 87.35 % and 83.13 %, respectively. Experimental comparison between TTS and NTS was carried out in the field. The results showed that the seeding accuracy of NTS was 83.13 % and the variation coefficient of seeding uniformity was 15.12 %. The results also showed that accuracy of NTS was consistent with theoretical value, and was significantly better than that of TTS. Meanwhile, NTS can save 6% seeds and 5% fertilizer. The wheat emergence of NTS was robust with a wide belt and no leaking, the emergence rate of NTS was 90.46 % with higher plant height and more root quantity than that of TTS. This research fills in a literature gap for wheat precision seeding technology.

Eucalyptus delegatensis is native to the Australian Alps (subsp. delegatensis) and montane Tasmania (subsp. tasmaniensis). Post-fire regeneration mechanisms of the obligate-seeder subspecies on the Australian mainland are well-known, but less is known about the resprouter Tasmanian subspecies. In January 2016, large tracts of Eucalyptus delegatensis forests in central Tasmania, logged at different intensities, were burnt by low- and high-severity fire. We used statistical modelling to understand how tree survival, vegetative regeneration and seedling recruitment differed according to understorey type, fire severity, logging intensity and tree size (DBH). Fire severity, defined as unburnt, low-severity (fire scarring on the stem and/or lower canopy burnt) and high-severity (full canopy burnt), affected tree survival: 84% of trees were alive in unburnt transects, compared with 43% in low-severity transects and 36% in high-severity transects. Epicormic resprouting was the dominant mode of vegetative recovery, with

This study aims to substantiate the parameters of a two-phase “air-seed” and “air-drop” flow for the numerical implementation of a mathematical model describing the operation process of the spiral mixing chamber of the proposed device for pre-sowing seed treatment with biological preparations (biologics) in the distribution system of the grain seeder. The requirements for creating a device, optimizing its technical parameters, and justifying the parameters of a two-phase flow are: gradual transition from chemical to biological preparations in terms of environmental friendliness of the process, pre-sowing seed treatment with biological preparations immediately before introduction into the soil and improving the treatment class. The requirement to improve the treatment class in compliance with the specified norm and uniform distribution of the biologics over the seed surface has been solved by redistributing the seed and drop concentration of the biological preparation in a unit of air flow volume using the effect of moving dispersed materials in the curved channel of the seed tube. Analytical studies of the distribution of seed and drop concentration of the biological preparation in a spiral mixer have been carried out. The modes of a two-phase “air-seed” and “air-drop” flow determined by the Reynolds number and the volume concentration of seeds and drops in the biologic are established. The method of aerodynamic calculation for determining the speed of air flow to provide the necessary seed and drop concentration of a biological preparation and pneumatic seed distribution in the distribution system of the drill is given to calculate the parameters of the two-phase flow of these mixtures. As a result, it was determined that after one mixer turn with a diameter of 600 mm, 95% of the aerosol is deposited on the chamber wall, and the throwing power of up to 85–90% is achieved in one spiral turn. The incrustation process in the air flow allows for fairly even seed processing with a working mixture consumption rate from 2 l/t to 25 l/t. The technology of seed treatment during sowing reduces the labor costs and time spent on pre-sowing seed treatment, ensures the effective use of biological preparations that require 2–24 h before sowing, and increases the yield by 5–10% depending on the preparation used.

This study is aimed at substantiating parameters of the two-phase “air-seeds” flow for the numerical implementation of a amathematical model describing the technological process of the grain seeder distribution system. The technique which was proposed can be further used to study and improve design and technological parameters of various pneumatic grain seeders. The “air-seed” flow regime is two-phase set by the Reynolds number and the bulk concentration of particles. To calculate these parameters, there is given an aerodynamic calculation of the air flow velocity to ensure the pneumatic distribution of seeds in the distribution system of the seeder. As the result, there were found: the air flow velocity for seed delivery and homogenous distribution on coulters for the entire pneumatic system; it was 8.71…9.1 m/s at the seed tube outlet (dispersion σ = 0,019, variation coefficient ν = 1,58%); mass concentration of seeds M = 0,92…7,1; volume concentration of seeds V = 8,4·10−4…6,5·10−3; Reynolds number of seeds 1250…4200; dynamic inertia of seeds τp = 0,63…4,72. The obtained parameters are necessary for numerical implementation of mathematical models for the technological process of the seeder pneumatic distribution system by two-phase flow mechanics.

In the extensive rice–wheat system of north-west (NW) India, harvesting is by large combines and the rice residues are normally burnt after harvest, followed by irrigation and intensive tillage prior to sowing wheat. While in-field retention of crop residues can play an important role in replenishing soil quality and reducing environmental pollution from stubble burning, until recently, there has been no suitable technology for seeding wheat in rice residues. To address this need, a series of machines (‘Happy Seeders’) was developed over the past 10 years, culminating in the development of version 2 of the 9-row Turbo Happy Seeder (v.2). The 9-row Turbo Happy Seeder(v.2) has a weight of 506 kg and can be operated by a 33.6 kW tractor at a work rate of 0.3 ha h−1. Numerous on-farm trials show that yield of wheat sown into rice residues with the 9-row Turbo Happy Seeder is similar to or higher than yield with straw burning and conventional tillage prior to sowing, while providing many benefits to the farmer. These include greatly reduced fuel consumption and cost of crop establishment, and the ability to sow as soon as desired after harvest, ensuring the possibility of sowing at the optimum time and reducing the need for irrigation. However, adoption has been low to date, despite a 50% price subsidy. Constraints to adoption include the low window of operation of the machine (25 days per year), the low machine capacity compared with conventional seed drills, the inability to operate in wet straw, and the lack of straw spreaders on combine harvesters. Removal of subsidies for diesel and electricity (for pumping groundwater) and implementation of the policy banning in-field straw burning would help to accelerate adoption of technology for direct drilling wheat into rice residues.

Real time weed detection could reduce herbicide inputs in fields but its application is constrained by weed/crop discrimination. This hurdle could be bypassed in crops like corn and soybean if weeds were detected on the inter-row only. However, using inter-row data to control weeds could be risky if weeds are more abundant on rows. A field study was carried out in the province of Quebec (Canada) to evaluate the effect of the planter unit and tractor wheels on relative weed cover, density and biomass between rows and inter-rows in corn and soybean when a post-emergence application of herbicide is scheduled. The experimental design included two sites, two fields per site, two years, and two crops. Treatments included: 1) seeded row (control) 2) unseeded row (seeder pass without crop seeds) and 3) tractor wheel (wheel tracked inter-row). Weed cover was evaluated using digital images and a custom made program. The absence of a crop on rows (unseeded vs. seeded rows) did not modify weed density and biomass before herbicide application in both corn and soybean. Weed density was always higher on rows than on inter-rows unless inter-rows had been tracked by tractor wheels indicating that soil disturbance by the planter and tractor wheels increased weed seed germination and subsequent seedling emergence. Weed cover on undisturbed inter-rows was generally lower or equivalent to weed cover on rows. Weed cover on inter-rows compacted by tractor wheels was always equivalent or higher than weed cover on rows. Using inter-rows to detect weeds could underestimate weed pressure in corn and soybean in Quebec, unless the inter-rows trampled by tractor wheels were scanned.

The current experiment, conducted in Ramhormoz, Iran, compared the energy consumption of two rice cultivation systems: direct seeded rice and transplanting cultivation systems. In the transplanting system, rice is grown by hand-transplanting thirty-day-old nursery seedlings into standing water in the main field. The direct cultivation system has no nursery or tillage operation. Instead, rice is cultivated in the main field using a cereal seeder. In this study, data was collected from 185 rice producers, 125 of whom used transplanting and 60 of whom used direct seeding as their rice growing system. The results indicated that the energy input of the two cultivation systems was significantly different in the use of diesel fuel, pesticide, electricity, irrigation, human labor, and total energy. Herbicide usage was higher in the direct seeding system than in the transplanting system, but other energy inputs were found to be higher in the transplanting system. The energy output of the transplanting system was higher than that of the direct seeding system. The energy input of the direct seeding system was lower than that of the transplanting system, resulting in a higher energy ratio, which suggests that the direct seeding system would increase energy efficiency and sustainability in rice production.

Soil enzymes are critical to soil nutrient cycling function but knowledge on the factors that control their response to major disturbances such as wildfires remains very limited. We evaluated the effect of fire-related plant functional traits (resprouting and seeding) on the resistance and resilience to fire of two soil enzyme activities involved in phosphorus and carbon cycling (acid phosphatase and β-glucosidase) in a Mediterranean shrublands in SE Spain. Using experimental fires, we compared four types of shrubland microsites: SS (vegetation patches dominated by seeder species), RR (patches dominated by resprouter species), SR (patches co-dominated by seeder and resprouter species), and IP (shrub interpatches). We assessed pre- and post-fire activities of the target soil enzymes, available P, soil organic C, and plant cover dynamics over three years after the fire. Post-fire regeneration functional groups (resprouter, seeder) modulated both pre- and post-fire activity of acid phosphatase and β-glucosidase, with higher activity in RR and SR patches than in SS patches and IP. However, we found no major differences in enzyme resistance and resilience between microsite types, except for a trend towards less resilience in SS patches. Fire similarly reduced the activity of both enzymes. However, acid phosphatase and β-glucosidase showed contrasting post-fire dynamics. While β-glucosidase proved to be rather resilient to fire, fully recovering three years after fire, acid phosphatase showed no signs of recovery in that period. Overall, the results indicate a positive influence of resprouter species on soil enzyme activity that is very resistant to fire. Long-lasting decrease in acid phosphatase activity probably resulted from the combined effect of P availability and post-fire drought. Our results provide insights on how plant functional traits modulate soil biochemical and microbiological response to fire in Mediterranean fire-prone shrublands. This work was supported by the research projects FEEDBACK (CGL2011-30515- C02-01), funded by the Spanish Ministry of Innovation and Science, and CASCADE (GA283068), funded by the European Union's Seventh Framework Programme (FP7/2007-2013).

Application of optical techniques to gaseous flows usually requires seeding the fluid with tracers sufficiently small to follow the flow, added in suitable concentrations. This work describes the design and manufacture of a seeder based on ultrasonic atomization of aqueous solutions or other fluids of similar viscosity, capable of operating in a continuous way with high atomization rates. It includes a dozen piezoceramic disks that oscillate at 1.65 MHz, generating droplets with Sauter mean diameter in the range of 4–5 μm and rates over 0.6 g/s when working with water. To test its performance, the device has been used to seed a simple free air jet issuing from a 3.5 cm diameter pipe. Initially the seeding density is very satisfactory, but if only water is nebulized the droplets evaporate in a short time and the concentration becomes too low when moving downstream. The situation can be greatly improved mixing the water with a less volatile liquid. Here, a small percentage of glycerol (5% in volume) has been added to the water to extend the droplet lifetime, although in general, atomization rate strongly decreases when increasing the liquid viscosity. The seeded flow has been visualized, and the 3D velocity field has been successfully measured using stereoscopic particle image velocimetry.

The purpose of this study was to research the influence of four different tillage practices [T1: Conventional tillage (moldboard plow+disk harrow+combined harrows+precision seeder); T2: Reduced tillage-I (cultivator+combined harrows+precision seeder); T3: Reduced tillage-II (rotary power harrow+precision seeder) and T4: No-till (no-till seeder)] on bulk density, total porosity, penetration resistance, field capacity, field water content and the infiltration rate of a loamy soil in a semi-arid region with a cool climate and an annual mean temperature of 5.6 °C. In particular, the effectiveness of the no-till practice was investigated. Since 1999, the experimental field has been tilled by the above-mentioned tillage practices and also applied a crop rotation (vetch–winter wheat–fallow) in dry conditions. We made assessments of selected soil properties according to the data during the sowing–germination period of winter wheat only in 2012 autumn. Therefore, the number of germinated seedlings of winter wheat was also evaluated. The data of this study carried out in three replications were statistically analyzed using the ANOVA and the regression technique. The results indicated that the tillage treatments affected soil properties and wheat germination. The highest values in all examined parameters except for total porosity were obtained under the no-till practice for top soil layer of 30 cm. As was expected, the no-till treatment had the highest bulk density and provided the lowest total porosity. Generally, the plots tilled by conventional practice had the lowest values. Similar results were obtained for the top soil layer of 0–10 cm, which is seedbed. The penetration resistance measured to a depth of 30 cm in 5 cm increments increased as polynomial with increasing the soil depth in all treatments. The infiltration rate decreases as a function of elapsed time could be described by the Kostiakov equation. Also, significant linear relationships were obtained for penetration resistance–bulk density, field capacity–bulk density and field capacity–penetration resistance. Although no-till treatment improved the hydraulic properties of soil, it had no positive effect on the soil physical properties. However, the linear relations with high correlation coefficients between penetration resistance and bulk density with field capacity at the no-till showed that soil physical and hydraulic properties revealed that they are connected to each other. According to the results of our study it could be concluded that the no-till practice increased winter wheat germination due to higher water content.

The air stream generated by the fan of pneumatic seeders – necessary to create a depression in the sowing element of the machine and to guarantee correct seed deposition – can blow away solid particles that have become detached from the seeds including the pesticide seed coating used for seed dressings. In this study, experimental tests were carried out to evaluate the performance of technical solutions by seeder manufacturers to limit dust drift. A specific test methodology was developed to assess seeder performance. The tested technologies that convey the air to the soil, independent of their design, reduced particle drift from seeds by more than 60% compared to a conventional machine with the fan outlet oriented upwards. Particle drift was reduced by more than 70% if only an area between 5 and 20 m downwind of the machine border was considered. This study has shown that the use of an appropriate design can reduce the dispersion of toxic seed coating dust in the atmosphere during seeding and that the methodology developed to carry out the trials could be used for seeder dust dispersion classification.

The factory raising seedlings is a large-scale concentrated raising seedlings method, which is often used to develop seedlings of rice, vegetable and flowers. The technology and application of factory raising seedlings were introduced in this paper. Three kinds of raising seedlings modes, which have been put in use in China, are small raising seedlings greenhouse, intelligent raising seedlings greenhouse and factory raising seedlings respectively. The disadvantages are that, they belong to tray raising seedlings mode which needs large fields and trays, and the labor intensity is too hard. In order to reduce the area and raise the level of raising seedlings mechanization, a kind of rice factory three-dimensional raising seedlings system was presented, which is consisted of greenhouse, seedlings frame, carpet seeder and so on. A new carpet raising seedlings was also put forward and can produce long seedlings carpet that is twice as wide as seedlings tray at least. And a carpet seeder designed can flat the nutritional tape into seedlings frame and put seeds and topsoil on the tape. Integrating with multiple stratifications, carpet raising seedlings and intelligent control technology, the factory three-dimensional carpet raising seedlings system provides technical support for the seedlings industrialization development in future.

Previous research on seed-regenerating eucalypt species (e.g. ash-type eucalypts) posits that water use by regenerating forests increases quickly after fire and may exceed that of mature forests (by as much as 100%) for periods of many decades. This hypothesis has not been tested in forests dominated by re-sprouting eucalypts. We examined the effect of fire on tree and stand-level water use in a resprouting mixed species eucalypt forests close to Stanley in north-east Victoria, Australia. In general, rates of water use in regenerating mixed-species eucalypt forests 3 years after fire were very similar to those for adjacent unburnt mature forests (0.48 ± 0.14 in regenerating vs. 0.66 ± 0.17 mm day −1 in unburnt forest, mean ± 0.95 CIs). This clear difference between resprouters and seeders corresponds to: slower sap flow in resprouting trees; a comparatively limited increase in sapwood area index (22% compared to 70% in Alpine ash forests); and a 20% decrease in total leaf area index after the fire. While the general climate differed little amongst study forests due to their close spatial proximity, vapour pressure deficit within unburnt was greater than regenerating forest and was the main control of tree water use, irrespective of species. Midday leaf water potential and measures of leaf physiology (except stomatal conductance) derived from gas-exchange measurements were similar between mature and resprouting trees, but the stomata of resprouting trees maintained a greater conductance to water vapour than mature leaves. A few years after crown-removing fires, water use by resprouting mixed-species eucalypt forests was little different to nearby mature forests. These results strongly contrast post-fire patterns in water use for the seeder (ash-type) eucalypt forests.

The present study analysed the constructive and operative parameters of pneumatic seeders and researched and assessed possible technical solutions for limiting the unwanted dispersion of dust from seed dressing during sowing of maize seeds. Tests were made on several maize pneumatic seeder models. The air flow rates and the air velocities at the fan outlet were assessed, the sizes of the areas contaminated with the material from the maize seeds was evaluated and the air velocities along the contour of the sowing machines were measured. Results showed that by decreasing the fan air flow rate by 30% it was possible to consistently reduce the size of the area contaminated by seed dressing dust while maintaining a good quality of seeding. They also showed that the technical solutions proposed by the seeder manufacturers reduced the environmental contamination with the pesticide-containing dust by more than 90%.

Strip tillage is a conservation practice in which narrow strips, generally totaling less than 50% of the field area, are tilled. We hypothesized that strip tillage would be beneficial for long-term soil quality improvement, erosion control, and environmental protection because it also protects crop residues so they can cover and continuously protect the soil surface. A two-year field experiment with three replicates was conducted to quantify effects of three strip widths on selected soil physical properties, seed emergence and yield of sunflower ( Helianthus annuus ). A powered row crop rotary hoe which is a group of narrow rotary tillers spaced evenly along the width of the toolbar and powered by the tractor power take-off was used to till soil in strips. The rotary hoe was equipped with C-type blades and was used to till strip widths of 37.5, 30 and 22.5 cm by changing the blade position and number of flanges on each row of the rotary hoe. A constant rotor rotational speed (370 rpm), forward tractor speed (5.4 km h −1 ) and tillage depth (10 cm) were used to create the three strip widths that corresponded to tilled zones encompassing 50, 40, and 30% of the field area, respectively. A pneumatic seeder with 75 cm row intervals was used for planting. The results show that as strip width increased, soil temperature increased but soil moisture content decreased due to evaporation loss from the tilled surface of the strips. Sunflower seed emergence ranged from 67 to 93%, with the lowest levels occurring with 22.5 cm strips. Plant length and stalk diameter also increased as strip width increased. Seed yields for the two years also increased with strip width, averaging 4.4, 4.1, and 3.9 Mg ha −1 for the 37.5, 30 and 22.5 cm strip widths, respectively. Based on these results, although seed yield was least for the 22.5 cm strip width, tractor fuel efficiency was greatest for that width and the soil tended to retain more moisture for that width, compared to the 30 and 37.5 cm widths, so the 22.5 cm strip width is recommended to the eastern Turkey.

In the current work evaluation of CO2 release velocity profiles is determined using Particle Image Velocimetry (PIV). The formation of solid CO2 particles using the rapid expansion of nozzle flow is used as a seeder particle, making the method truly nonintrusive and negates the use of special seeder equipment. Preliminary tests have been conducted on low speed large CO2 particles. High-speed release PIV experiments have been conducted for a range of storage pressures between 60 and 150 bars using a 13mm (1/2 inch) diameter nozzle. The current paper is reporting combined research with a second paper by Dam et al. [4]. The current investigation is a small scale experiment prior to reported mid scale experiments reported in Ahmed et al. [5].

The aim of this study is to determine the effects of no-till seeders with different furrow openers, stubble heights and positions on soil bulk density, cone index, sowing performance and seed emergence of common vetch seed. Three different types of no-till seeders (hoe, disc and wing hoe type openers) were used on two different stubble heights (short and long) and two different stubble positions (standing and flat). Obtained results concluded that the no-till seeders with hoe-type furrow opener provided better sowing performance and seed emergence in comparison to the no-till seeders with disc- and wing hoe-type furrow openers. The highest emergence percentage in the study was obtained using no-till seeder with hoe-type furrow openers (77.13%). The minimum dry bulk density (1.18 and 1.23 Mg m−3 in 0–5 cm and 5–10 cm soil layers, respectively) and penetration resistance (0.75 MPa and 0.81 MPa in 0–5 cm and 5–10 cm soil layers, respectively) values of soil were observed at the plot sowing using no-till seeder with wing hoe type furrow opener. In addition to these, the best results of sowing performance and seed emergence were observed at the plots with short and standing stubble conditions. The emergence percentage decreased with the increase in the stubble height (76.15% and 69.31% at 12 cm and 24 cm stubble heights, respectively).

Piglets (n = 128) weaned at 21 days of age were used in a 35-day seeder model to evaluate the effects of dietary additives differing in active ingredients, chemical, and physical formulation, and dose on Salmonella colonization and shedding and intestinal microbial populations. Treatments were a negative control (basal diet), the positive control (challenged, basal diet), and six treatments similar to the positive control but supplemented with the following active ingredients (dose excluding essential oils or natural extracts): triglycerides with butyric acid (1.30 g kg(-1)); formic and citric acids and essential oils (2.44 g kg(-1)); coated formic, coated sorbic, and benzoic acids (2.70 g kg(-1)); salts of formic, sorbic, acetic, and propionic acids, their free acids, and natural extracts (2.92 g kg(-1)); triglycerides with caproic and caprylic acids and coated oregano oil (1.80 g kg(-1)); and caproic, caprylic, lauric, and lactic acids (1.91 g kg(-1)). On day 6, half the piglets (seeder pigs) in each group were orally challenged with a Salmonella Typhimurium nalidixic acid-resistant strain (4 × 10(9) and 1.2 × 10(9) log CFU per pig in replicate experiments 1 and 2, respectively). Two days later, they were transferred to pens with an equal number of contact pigs. Salmonella shedding was determined 2 days after challenge exposure and then on a weekly basis. On day 34 or 35, piglets were euthanized to sample tonsils, ileocecal lymph nodes, and ileal and cecal digesta contents. The two additives, both containing short-chain fatty acids and one of them also containing benzoic acid and the other one also containing essential oils, and supplemented at more than 2.70 g kg(-1), showed evidence of reducing Salmonella fecal shedding and numbers of coliforms and Salmonella in cecal digesta. However, colonization of tonsils and ileocecal lymph nodes by Salmonella was not affected. Supplementing butyric acid and medium-chain fatty acids at the applied dose failed to inhibit Salmonella contamination in the current experimental setup.

The no-till seeders of various soil opener configurations have been shown to produce various soil physical responses in relation to soil and climate conditions, thus affecting crop performance in permanent raised beds (PRB) systems. This is particularly important in arid Northwest China where large volumes of residue are retained on the soil surface after harvest. In Zhangye, Gansu Province, China, a field trial assessed the effects of three typical (powered-chopper, powered-cutter and powered-disc) PRB no-till seeders and one traditional seeder on soil disturbance, residue cover index, bulk density, fuel consumption, plant growth, and subsequent yield. In general, seedbed conditions and crop performance for PRB no-till seeders seeded plots were better than for traditional seeded plots. In PRB cropping system, the powered-chopper seeder decreased mean soil disturbance and increased residue cover index compared to powered-disc and -cutter seeders. However, the results indicated that soil bulk density was 2.3–4.8% higher, soil temperature was 0.2–0.6°C lower, and spring wheat emergence was 3.2–4.7% less. This was attributed to greater levels of residue cover and firmer seedbeds. Spring maize and wheat performance in the powered-cutter and -disc treatments was better (non-significant) than powered-chopper treatment. So powered disc no-till seeder, which generally provided the best planting condition and the highest yield, appeared to be the suitable seeder in heavy residue cover conditions. Considering the precision requirements for soil disturbance and residue cover, the powered strip-chopping no-till seeder could be a suitable option for PRB cropping system in Northwest China. Although these results are preliminary, they are still valuable for the design and selection of no-till seeders for PRB cropping systems in arid Northwest China.

Field experiments were conducted for two years during 2005–2006 and 2006–2007 in farmers’ fields at Sorajgonj Village in Sadar Upazila of Chuadanga District in Bangladesh. The objective was to evaluate the comparative efficacy of hand weeding and pretilachlor applied at different days after seeding (DAS) rice in effectively and economically controlling weeds and improving the productivity of rice wet-seeded using a drum seeder, during the aman and boro seasons. Three application timings of pretilachlor and five weed control treatments, including (a) pretilachlor 0.500 kg ha −1 , (b) pretilachlor 0.375 kg ha −1 , (c) pretilachlor 0.250 kg ha −1 , (d) hand weeding thrice, and (e) unweeded (check), were tested. The reduction in grassy weeds due to different rates of pretilachlor and hand weeding thrice was inconsistent due to less efficacy of pretilachlor against Cynodon dactylon and incomplete removal of the same weed by hand weeding. The density and biomass of sedges and broad-leaved weeds at different pretilachlor rates were lower than or similar to those of hand weeding thrice during both seasons. On average, rice yield loss due to uncontrolled weeds was 43% and 51% in aman and boro seasons, respectively. Economic analysis revealed that the net income with pretilachlor application was equivalent to that obtained with hand weeding thrice in the boro season and higher than with hand weeding thrice in the aman season, in spite of getting slightly lesser rice yield with pretilachlor usage than with hand weeding thrice. Results of the study revealed that, for effectively controlling associated weeds and attaining optimal wet-seeded rice productivity and net returns, pretilachlor 0.250 kg a.i. ha −1 or 0.375 kg a.i. ha −1 application at 3 or 5 DAS in aman and at 7 or 9 DAS in boro season can be used as an alternative to hand weeding thrice, during the times of labor scarcity in Bangladesh.

Plant communities are often composed of species belonging to different functional groups, but relatively few studies to date have explicitly linked their spatial structure to the outcome of the interaction among them. We investigated if mortality of seeder species during their establishment after fire is influenced by the proximity of the resprouter herb Brachypodium retusum . The study was conducted in a Mediterranean shrubland (00°39′ W; 38°43′ N), 40 km northwest of Alicante (Spain) with Ulex parviflorus , Cistus albidus , Helianthemum marifolium , and Ononis fruticosa as dominant obligate seeder species and a herbaceous layer is dominated by the resprouter B. retusum . We followed the fate of mapped seedlings and the biomass of B. retusum one, two, three and nine years after an experimental fire. We used point pattern analyses to evaluate the spatial pattern of mortality of seeder species at these years in relation to the biomass of B. retusum . We hypothesize that B. retusum may initially have a positive impact on seeder survival. We implemented this hypothesis as a point process model that maintains the overall number of dead seeder plants, but seeder survival varied proportionally to the biomass of B. retusum in its neighborhood. We then contrasted this hypothesis with a previous analysis based on a random mortality hypothesis. Our data were consistent with the hypothesis that proximity of B. retusum reduced the mortality of seeder plants at their establishment phase (i.e., 2 yrs after fire). However, we found no evidence that B. retusum influenced seeder mortality when plants grow to maturity. We also found that, under the more stressful conditions (fire + erosion scenario), B. retusum had a lower impact on the performance of seeder species. Our results suggest that B. retusum may reduce negative density-dependent effects among neighboring seeder plants during the first years after fire.

Resilience against sudden changes in the environment is a very desirable trait in plants used for ecosystem restoration. Mediterranean-like vegetation exhibits particularly strong fire resilience. There are two main functional groups of fire-prone species among Mediterranean-like vegetation: seeders and resprouters. Our aims were to describe how the theory of succession after fire relates to rehabilitation and to use this knowledge to improve the results of rehabilitation attempts in Mediterranean-like ecosystems. Eight post-fire (PF) sites, 14 post-rehabilitated (PR) quarry sites and two woodland sites were sampled. Detrended Canonical Correspondence Analysis (DCCA) showed that PF and PR successions were quite different. Both displayed an increasing abundance of resprouters over time, but seeder density increased throughout PR succession and decreased during PF succession. Nine species were common to both successions in all studied stages. The results showed that until 15–21 years of succession, the post-rehabilitation sites had not become as resilient to fires as sites populated by indigenous vegetation due to the lack of a seeder seed bank. However, after 21 years of PR succession, the exponentially increasing seeder population may allow for seed bank formation and thus eventually improve the fire resilience of the site.

Normally, the data generated from farmer participatory trials (FPT) are highly unbalanced due to variation in the number of replicates of different treatments, the use of different varieties, farmers’ management of the trials, and their preferences for testing different treatments. The incomplete nature of the data makes mixed models the preferred class of models for the analysis. When assessing the relative performances of technologies, stability over a range of environments is an important attribute to consider. Most of the common models for stability may be fitted in a mixed-model framework where environments are a random factor and treatments are fixed. Data from on-farm trials conducted in the Indo-Gangetic Plain (IGP) of South Asia under the umbrella of Rice–Wheat Consortium (RWC) were analyzed for grain yield stability using different stability models. The objective was to compare improved resource management technologies with farmers’ practice. The variance components of an appropriate mixed model serve as measures of stability. Stability models were compared allowing for (i) heterogeneity of error variances and (ii) heterogeneity of variances between environments for farmers-within-environment effects. Mean comparisons of the treatments were made on the basis of the best fitting stability model. Reduced-till (non-puddled) transplanted rice (RT-TPR) and reduced-till drill-seeded wheat using a power tiller – operated seeder with integrated crop and resource management RTDSW(PTOS)ICRM ranked first in terms of both adjusted mean yield and stability.

The performance of a vacuum-cylinder seeder for the precision sowing of rape seeds was investigated. For releasing seeds from nozzles smoothly, a positive differential pressure was applied to the seed. The forces acting on the seeds in free flight were calculated using the computational fluid dynamics (CFD) software Fluent. Using the differential equation for seed motion, seeds falling trajectories using different working parameters were numerically determined. A high-speed camera system mounted on a laboratory seeder test-rig was used to record the motion of seeds. A mean shift algorithm for tracking seeds was used. The horizontal displacement x and the fall time t f of seeds predicted by the numerical analysis and measured by the high-speed camera system were compared. The results indicated that the relative errors of x and t f were Based on the analysis of seeds falling trajectories, it was found that the variations of positive differential pressure Δ p and release angle θ had significant effects on seeding uniformity. In order to analyse their effects on horizontal displacement, a coefficient of positive differential pressure variation χ p and coefficient of sowing angle variation χ θ were proposed and their values calculated. Calculations indicated that the optimum levels for Δ p and θ for the precision seeding of rape seeds were in the range of 1–2 kPa and from −10 to 0°, respectively. Experiments were carried out on the vacuum-cylinder precision seeder test-rig and the results showed that the average seed spacing interval error reached the minimum at Δ p = 1.5 kPa and θ = −5° and that the error increased almost linearly with increasing of cylinder rotational speed.

Site-specific crop management is a technology that modulates the application rate of field inputs such as seeds, fertilizers, and herbicides based on the needs of each management zone within a field. There are two methods available for changing the seeding rate in fluted-feed-roll type seed drills: (1) changing the active feed-roll length and/or, (2) changing the seed meter drive shaft speed. A possible method to develop a variable-rate seeder is to add a controller to a conventional grain drill which can change the speed of the seed meter drive shaft on-the-go. This was explored in the present study with the following main objectives: (a) to design a DC electric variable-rate controller to change a grain drill from a uniform to a variable-rate seeder, and (b) to determine the response time of the system. A motor control circuit was designed which used the output signals of two encoders as feedback. The system was consisted of: (1) a DC motor with a fixed-ratio gearbox, (2) encoders for sensing the rotational speeds of the grain drill drive wheel and the motor, (3) a GPS receiver, (4) a pulse-with-modulation (PWM) DC motor controller, and (5) a laptop. Dynamic tests were conducted at application rates of 87.5 (low) and 262.5 (high) kgha^-^1. Sigmoid equations were best fitted to the transition data from low-to-high and high-to-low seeding rates. Our findings showed that the response times of low-to-high and high-to-low transition rates were 7.4 and 5.2s, respectively.

Conventional tilled transplanting, a widely practiced method of rice (Oryza sativa L.) establishment in puddled soils in rice–rice and rice–wheat (Triticum aestivum L.) systems in Asia, requires a large amount of labor and water, which are becoming scarce and expensive. Growing more food with the same production costs or even reduced costs and sustaining the quality of the natural resource base are a major concern. On-farm trials were conducted in Chuadanga District of Bangladesh during the wet season as monsoon rice (aman) and during the dry season as winter rice (boro) in 2006–07 to evaluate the effects of establishment methods with improved crop management on productivity, resource (land, water, and labor) use, and economic return. Rice was established by sowing in line with a drum seeder on conventional tilled puddled soils (CT-DrumR) and by transplanting in line on the day of CT-DrumR (CT-TPR1) and 30 and 35 days after CT-DrumR (CT-TPR2) in aman and boro seasons, respectively. Farmers’ usual transplanting time corresponds to the day of CT-TPR2. Grain yields in CT-DrumR and CT-TPR2 were similar but the crop occupied the main field 22–24 days longer in CT-DrumR than in CT-TPR2, resulting in lower productivity (45 kg grain ha−1 day−1 vs. 55 kg grain ha−1 day−1) in both seasons. Drum-seeded rice matured earlier by 8 and 11 days, received 12% and 6% less irrigation water, saved 19 and 24 person-days ha−1, and gave higher gross margins of 6% and 4% but input costs increased by 20% and 12% than CT-TPR2 in aman and boro seasons, respectively. There is a need to examine these benefits of drum-seeded rice in relation to the feasibility of adoption by farmers.

The purpose of this research was to examine the performance of a modified precision vacuum seeder for no-till sowing of maize ( Zea mays L.) and soybean ( Glycine max L.) following wheat ( Triticum aestivum ). A wavy-edged disc and side gauge wheels were fabricated and mounted to each unit of a common precision vacuum seeder (with a hoe opener on one row unit and a double disc-type opener on another row unit) and used to sow at three forward speeds (1.0, 1.5 and 2.0 m s −1 ). Multiple index, miss index, quality of feed index and precision of the distribution of the seeds along the length of the row, sowing depth uniformity, mean emergence time and percent emergence were determined. Sowing depth uniformity, mean emergence time and percent emergence of both maize and soybean seeds were decreased and precision of the distribution of the seeds along the length of the row was increased as a result of increasing forward speed. The distribution of the seeds along the length of the row, sowing depth uniformity and percent emergence of the seeder equipped with the double disc-type opener was better than the seeder equipped with the hoe-type opener. The precision of the distribution of the seeds along the length of the row for forward speeds of 1.0 and 1.5 m s −1 experienced in this study was well below 29%, and therefore is acceptable for both maize and soybean seeds. The modified precision vacuum seeder generally performed best using the double disc-type furrow opener at the forward speed of 1.0 m s −1 , based on the distribution of the seeds along the length of the row, sowing depth uniformity, and percent emergence.