The growing demand for agricultural output and limited resources encourage precision applications to generate higher-order output by utilizing minimal inputs of seed, fertilizer, land, and water. An electronically operated planter was developed, considering problems like ground-wheel skidding, field vibration, and the lack of ease in field adjustments of ground-wheel-driven seed-metering plates. The seed-metering plate of each unit of the developed planter is individually driven by a brushless direct current (BLDC) motor, and a BLDC motor-based aspirator is attached for pneumatic suction of seeds. The revolutions per minute (RPM) of the seed-metering plate are controlled by a microcontroller as per the received data relating to RPM from the ground wheel and the current RPM of the seed-metering plate. A feedback loop with proportional integral derivative (PID) control is responsible for reducing the error. Additionally, each row unit is attached to a parallelogram-based depth control system that can provide depth between 0 and 100 mm. The suction pressure in each unit is regulated as per seed type using the RPM control knob of an individual BLDC motor-based aspirator. The row-to-row spacing can be changed from 350 mm to any desired spacing. The cotton variety selected for the study was RCH 659, and the crucial parameters like orifice size, vacuum pressure, and forward speed were optimized in the laboratory with the adoption of a central composite rotatable design. An orifice diameter of 2.947 mm with vacuum pressure of 3.961 kPa and forward speed of 4.261 km/h was found optimal. A quality feed index of 93% with a precision index of 8.01% was observed from laboratory tests under optimized conditions. Quality feed index and precision index values of 88.8 and 12.75%, respectively, were obtained from field tests under optimized conditions.

This study presents a new technique i.e., mobile application (Petiole), to estimate the leaf area, of two plant species (Neem & Rose), in the present study. It helps avoid the complex coding and algorithms required in the measurement of leaf area using the image processing techniques. The research's main objective was to evaluate the effect of the calibration height on the performance of the proposed new technique. The results exhibited that leaf area error was observed less than 1 cm2, for both plant species. The study also showed a non-significant effect of calibration height on the performance of the mobile application. The maximum error (cm2) was noticed with increasing calibration height from H1 to H3, but was less than 1 cm2. This study also reported that results of leaf area estimated by the mobile application were agreed with that of the grid count method.

Pneumatic planters are widely adopted in precision agriculture due to their superior field performance and minimal seed damage. However, variations in seed size, shape, and orientation can affect the ability of each orifice to pick and release a single seed accurately. Seed metering units typically incorporate seed cut-off and knock-out devices to improve singulation and ensure timely seed dropping, enhancing the quality feed index and reducing the precision index. These auxiliary devices—whether mechanical, electronic, pneumatic, or magnetic—increase system complexity, require skilled operation, necessitate additional maintenance, consume more energy, and heighten the risk of seed damage. The suctioned seed experiences impact from the seed metering plate during picking, and orifices are not fully sealed after seed pick-up, leading to a need for higher vacuum pressure. Additionally, field vibrations can adversely affect planter performance. To overcome these issues, this study developed a novel flexible orifice seed metering plate and optimised its operating parameters for cotton seed, adopting a central composite rotatable design (CCRD). The plates were developed by adding a layer of elastomeric material on rigid seed metering plate. The experiments were conducted using a developed electronic sticky belt setup in laboratory. An orifice diameter of 3 mm, vacuum pressure of 3.40 kPa, forward speed of 4.67 km/h, extended radius of 1 mm and coating thickness of 0.25 mm were found optimum with a quality feed index of 97.289% and precision index of 4.653%. Minimal difference between laboratory and field performance was noted when operated by an electronic planter. The miss index, multiple index, and precision index obtained under field conditions with rigid seed metering plate were found to be 4.4, 2.8, and 9.08% higher than coated seed metering plate, respectively. A comparatively lower optimal vacuum pressure and higher operation speed was achieved when coated seed metering plate was used in place of rigid seed metering plate. Hence coated seed metering plate can be a low-cost solution to achieve higher speed of precision planting with improved seeding performance. Graphical Abstract

There are numerous techniques for the estimation of leaf area. Every technique has some advantages and disadvantages over one another. This study proposed a new technique for the leaf area estimation i.e. mobile application (Petiole). It is a free of cost mobile application. The mobile application was used for the estimation of the leaf area of six different plant species. It was observed that error percentage for the leaf area estimation was recorded less than 4% in case of banyan, Jamun and lemon plant leaf. It was also concluded that less than 3 cm2 area error was present for all the cases. This study confirmed the reliability, correctness and robustness of the mobile application for leaf area estimation. This study ensures the accuracy and capability of the petiole app to mitigate the problems of laborious, cumbersome and expensive experiments for the leaf area estimation and the method also saved a lot of time as compared to the other methods. It has the potential to avoid the complex coding algorithm for the program based techniques, usually adopted for the measurement of the leaf area.

A tunnel sprayer has distinct recycling systems, which save a significant portion of the applied pesticide. Its performance is directly or indirectly influenced by various constructional parameters of the recycling system (nozzle spacing, nozzle angle, tunnel opening, and fin pitch) because they influence the movement of spray droplets, characteristics of the droplets, and recycling rate of the system. Therefore, the effect of these parameters was investigated for improvement in the tunnel sprayer’s performance. In this study, four adjustment mechanisms were developed for selected parameter’s regulation and tested using a hybrid tree (artificial and natural leaf). The non-significant results of spatial spray distribution revealed its accuracy and potential ability for maintaining spray uniformity across the tree canopy, except in the central zone of both trees. By considering the poor spray deposits at the central zone of both trees, the statistical analysis was carried out for spray deposits maximization and recycling rate minimization. The spray deposits varied from 1.016 × 10^− 4 to 2.944 × 10^− 4 µg/mm² and offered better plant protection. The sprayer saved up to 42.36% of the applied pesticide, which ensures economical farm operations and saves the environment. The optimized values for input parameters (i.e., X1: 350 mm, X2: 42.5 degrees, X3: 1100 mm, and X4: 41 mm) would improve the efficiency of the tunnel sprayer and conserve costly input resources.

A study for evaluating the soil pulverisation caused by different tillage practices, like harrow-cultivator-planker, rotavator practice and spading tillage machine was undertaken in the fields. The experiment was carried out at the fields of two different soil types viz. sandy loam (S1) and silty loam (S2). Six tillage practices, designated as P1, P2, P3, P4, P5 and P6, were undertaken in the present study. The six practices were one pass of harrow-cultivator-planker combination (P1), two passes of harrow-cultivator-planker combinations (P2), one pass of rotavator (P3), two passes of rotavator (P4), one pass of spading tillage machine (P5) and two passes of spading tillage machine (P6). Different implements have their own, i.e. different recommended speeds and depths of operation. For experimental study, two different depths of cut ranges, designated as D1 & D2 and two forward velocity ranges, designated as V1 & V2, suitable to every implement, were selected. The experiments have been laid out by using factorial in randomized block design, henceforth designated as f-RBD, of statistical methods to minimize variation of soil properties on the treatments. In order to find out the soil pulverisation caused by different tillage practices taken in the present study, each treatment was replicated three times. The mean weight diameter of soil clods formed after different tillage practices were found to be smaller in sandy loam soil as compared to silty loam soil.