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Item Soil nitrogen dynamics affected by coffee (coffea arabica) canopy and fertilizer management in coffee-based agroforestry(Springer Nature BV in cooperation with ICRAF, 2024-08) Kurniawan S; Nugroho RMYAP; Ustiatik R; Nita I; Nugroho GA; Prayogo C; Anderson CWNNutrient management in coffee-based agroforestry systems plays a critical role in soil nitrogen (N) cycling, but has not been well documented. The objective of this study was to evaluate the effect of coffee canopy management and fertilization on soil N dynamics. This study used a randomized complete block design (2 × 3 × 2) with four replications. There were three factors: 1) coffee canopy management (T1: Pruned, T2: Unpruned), 2) fertilizer type (O: Organic, I: Inorganic; M: 50% Organic + 50% Inorganic), and 3) fertilizer dose (D1: low, D2: medium, D3: high). Soil N dynamic indicators (i.e., total N, ammonium (NH4+), nitrate (NO3−), net N-NH4+, net N-NO3−, soil microbial biomass N) were measured at two soil sampling depths (0–20 cm and 20–40 cm). Results showed that pruning increased soil total N and microbial biomass N (MBN) by 10–56% relative to unpruned coffee trees. In contrast, the unpruned coffee canopy had 15–345% higher NH4+, NO3−, net N-NH4+, net N-NO3−, and microbial biomass N concentration than pruned coffee. Mixed fertilizer application increased NO3− and net N-NH4+ accumulation by 5–15% relative to inorganic and organic fertilizers. In addition, medium to high dose fertilization led to a 19–86% higher net N-NO3− concentration and microbial biomass N as compared to low dose fertilization. The treatment of no pruning and mixed fertilizer at low to medium doses was the optimal management strategy to maintain soil available N, while pruning combined with organic fertilizer has the potential to improve soil total N and MBN.Item Tree pruning/inspection robot climbing mechanism design, kinematics study and intelligent control : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Mechatronics at Massey University, Manawatu Campus, New Zealand(Massey University, 2018) Gui, PengfeiForestry plays an important role in New Zealand’s economy as its third largest export earner. To achieve New Zealand Wood Council’s export target of $12 billion by 2022 in forest and improve the current situation that is the reduction of wood harvesting area, the unit value and volume of lumber must be increased. Pruning is essential and critical for obtaining high-quality timber during plantation growing. Powerful tools and robotic systems have great potential for sustainable forest management. Up to now, only a few tree-pruning robotic systems are available on the market. Unlike normal robotic manipulators or mobile robots, tree pruning robot has its unique requirements and features. The challenges include climbing pattern control, anti-free falling, and jamming on the tree trunk etc. Through the research on the available pole and tree climbing robots, this thesis presents a novel mechanism of tree climbing robotic system that could serve as a climbing platform for applications in the forest industry like tree pruning, inspection etc. that requires the installation of powerful or heavy tools. The unique features of this robotic system include the passive and active anti-falling mechanisms that prevent the robot falling to the ground under either static or dynamic situations, the capability to vertically or spirally climb up a tree trunk and the flexibility to suit different sizes of tree trunk. Furthermore, for the convenience of tree pruning and the fulfilment of robot anti-jamming feature, the robot platform while the robot climbs up should move up without tilting. An intelligent platform balance control system with real-time sensing integration was developed to overcome the climbing tilting problem. The thesis also presents the detail kinematic and dynamic study, simulation, testing and analysis. A physical testing model of this proposed robotic system was built and tested on a cylindrical rod. The mass of the prototype model is 6.8 Kg and can take 2.1 Kg load moving at the speed of 42 mm/s. The trunk diameter that the robot can climb up ranges from 120 to 160 mm. The experiment results have good matches with the simulations and analysis. This research established a basis for developing wheel-driven tree or pole climbing robots. The design and simulation method, robotic leg mechanism and the control methodologies could be easily applied for other wheeled tree/pole climbing robots. This research has produced 6 publications, two ASME journal papers and 4 IEEE international conference papers that are available on IEEE Xplore. The published content ranges from robotic mechanism design, signal processing, platform balance control, and robot climbing behavior optimization. This research also brought interesting topics for further research such as the integration with artificial intelligent module and mobile robot for remote tree/forest inspection after pruning or for pest control.Item An evaluation of the production and profitability of alternative management regimes for Pinus radiata on a high fertility site : a thesis presented in partial fulfilment of the requirements for the degree of Master of Applied Science in Plant Science at Massey University(Massey University, 1997) Blair, Alexander JasonConversion of farmland to forestry is occurring at the rate of approximately 60,000ha/annum, much of it on hill country sheep and beef properties. The potential productivity of ex farm sites is high, mainly due to improved soil fertility but may produce trees with defects such as excessive branching, large branches and stem malformations. Adapting silvicultural practices to suit plantations on high fertility sites is necessary to effectively utilise this potential. However, many of the tools available for planning and assessing alternative silvicultural options in Pinus radiata stands have limitations for farm sites. This study utilises a 12.5ha stand of Pinus radiata established in 1973 on a Manawatu hill country sheep and beef property. Currently 'Tuapaka' has 31.3ha of Pinus radiata occupying land use capability class VI and VII. Of this total, 12.5ha is nearing maturity, while remaining areas are now reaching a stage where decisions on silvicultural management are necessary. The growth modelling system, STANDPAK, was used as an aid for developing and evaluating silvicultural options on Tuapaka. Existing Pinus radiata growth models have been primarily derived from traditional forest site data. They can be utilised for simulating growth on ex farm sites but will generally provide more accurate predictions of growth and yield if they are configured with local growth data. The EARLY and NAPIRAD growth models are recommended for simulating the growth of Pinus radiata on farm sites and formed the basis for the simulation of the Tuapaka stand. Inventory data, including diameter at breast height, mean crop height, and stocking were collected from the existing 12.5ha stand and used to configure these growth models and other STANDPAK components. Site index at Tuapaka was found to be 23m, with a high basal area increment potential. The best STANDPAK configuration combined the growth models EARLY (high +20% basal area increment) and NAPIRAD (switched at mean top height 18m). The results from this configuration predicted basal area to within 6% of the field estimate. These configurations were used to simulate and evaluate the growth of a new stand (at the 1ha level) for both clearwood and framing regimes. The combined influence of low site index and high basal area increment created problems associated with maintaining a target diameter over stubs (DOS) while utilising an acceptable number of pruning lifts. The required number of pruning lifts to achieve a 6.0m pruned height was able to be manipulated by delaying thinning, reducing the green crown length (CRL) at the first and second lifts, and maintaining a high ratio of unpruned trees through to thinning. Net present value (NPV) was primarily used as the selection criteria to determine the best regimes, because it reflects the final harvest revenues and associated silvicultural costs. The most profitable regime required a 3 lift pruning schedule. This regime provided the best compromise between final harvest value and silvicultural costs and was achieved by severe early pruning (CRL of 2.0m and 2.2m), delayed thinning, and maintaining a high ratio of unpruned to pruned trees. Clearwood regimes were more profitable than the framing regimes because of a higher average timber value which more than compensated for increased silvicultural costs and reduced log volume. The clearwood regime produced a final merchantable volume of 698m3 /ha, of which 37% graded in the higher value pruned log class. This regime had a pre tax net revenue of $39,500/ha and an NPV of $2,681/ha (8% discount rate). In contrast, the best framing regime produced a merchantable volume of 787m3/ha, a net revenue of $18,800/ha, and a NPV of $1,100/ha. The best clearwood and framing regime were subjected to economic analysis at the estate level (31.3ha) to determine the best silvicultural options for existing and future stands on Tuapaka. The clearwood regime was the most profitable, having a pre tax IRR of 9.1%, compared with 7.6% for the framing regime. These returns are likely to exceed the potential returns from farming, particularly on steep hill country.