https://hdl.handle.net/10182/44 2018-01-25T15:15:19Z https://hdl.handle.net/10182/8895 Changing New Zealand dairy farm systems Greig, Bruce J. There have been dramatic changes in New Zealand dairy farm systems over the last decade. There is evidence that the basic grass dependant dairy farm systems are becoming more intensive with greater amounts of supplementary feed. Basic economic and business principles can explain why this shift is occurring. The study of elementary production economic principles which guide the development of a chosen farm system are explored in this paper. New Zealand literature has examined different dairy production systems (Hedley, 2006; Newman, 2009) but few have ever done so from an economic imperative. All this literature has failed to mention that the key driver of profit and therefore the choice of farm system is dependent on relative prices i.e. the price of inputs (Px) vs. the milk price (Py). One element of the farm system debate is about high vs. low input. This debate has been part of the dairy industry for decades, both locally and overseas. In New Zealand researchers have concentrated on the scientific principles (animal nutrition and substitution rates) rather than the economic ones. The questions are essentially can farmers make more profit from higher (and sometimes more expensive) feed inputs, and what combination of feed inputs will achieve this, and what are the risks? 2012-01-01T00:00:00Z https://hdl.handle.net/10182/8795 Fertilizers in New Zealand, 1867-1929 McCaskill, L.W. In 1869, New Zealand use 216 tons of imported fertilizers in addition to a very small amount of local bonedust. Sixty years later, the imports amounted to 324,145 tons, while local production was in the neighbourhood of 35,000 tons. The increase in phenomenal particularly over the last few years. It is now realised fairly generally that we have banked too much on “stored fertility”. It was perhaps only natural, in the first few decades of farming in New Zealand with huge areas of the soil, that farmers should be prodigal of nature’s resources. But with the exhaustion of the virgin fertility, and the ever increasing demand and competition for land, it came to be realised very gradually, that more production was required from the existing land in occupation. Also, if possible, land previously thought useless should be made to produce. The key to both problems was found in the use of fertilizers. An attempt to trace the development of such practice forms the basis of this essay. As far as can be ascertained no previous investigation has been undertaken. Some of the outstanding points resulting from the enquiry are as follows: The importance of statistics to the investigator The pioneer work of the Canterbury Agricultural College The overwhelming importance of phosphates in general and superphosphate in particular The rise of topdressing The useful work of the Department of Agriculture The decline of the importance of local production 1929-01-01T00:00:00Z https://hdl.handle.net/10182/8635 Combined effects of cotyledon excision and nursery fertilization on root growth, nutrient status and outplanting performance of Quercus variabilis container seedlings Shi, W.; Bloomberg, Mark; Li, G.; Su, S.; Jia, L. Artificial excision of the distal part of acorns in order to promote germination is well researched in oak seedling cultivation studies. However, studies of combined effects of cotyledon excision and nursery fertilization on container seedlings are lacking, especially for seedling root growth and outplanting performance. This study aimed to explore the main effects of cotyledon excision on Quercus variabilis seedling emergence characteristics and demonstrated the combined effects of cotyledon excision and nursery fertilization on seedling quality to improve Quercus variabilis seedling outplanting performance. Four cotyledon excision treatments and two classes of nursery fertilization were implemented. Seedling emergence was noted every week after sowing. Seedling dry mass, morphology, and nutrient status were assessed at the end of the nursery season. After the first outplanting season, the aforementioned measurements along with seedling survival were determined once again. The results showed that cotyledon excision generally induced greater and more rapid seedling emergence, but did not affect shoot emergence synchronicity. The highest total emergence and emergence rate occurred with Intermediate excision (1/2 of the distal end of acorn was excised). Effects of nutrient loss due to cotyledon excision on seedling quality and outplanting performance were somewhat compensated by nursery fertilization. Nursery fertilization promoted dry mass increment (the net increment from T₀ to T₂ for dry mass) for excised seedlings after outplanting, resulting in better performance for Slight (1/3 of the distal end of acorn was excised) and Intermediate excision treatments in the field. Thus we conclude Intermediate excision combined with reasonable nursery fertilization can be recommended for production of nursery grown seedlings for afforestation. 2017-01-01T00:00:00Z https://hdl.handle.net/10182/8631 Developing a framework for growth modelling in a managed southern black beech forest Ganivet, E.; Moltchanova, E.; Bloomberg, Mark Background: A model of individual tree growth using simple predictors in a managed black beech (Fuscospora solandri (Hook.f.) Heenan & Smissen) forest could provide a useful tool for predicting future stand characteristics. Methods: Data from permanent sample plots were used to develop a framework for modelling individual tree growth in Woodside forest, a managed black beech forest in north Canterbury (New Zealand). We tested three mixed-effect models to identify effects of sites, treatment (thinnings), individual tree size and competition on tree growth rates. Results: A power function amended with variables specifying stand basal area and thinning treatment was best suited for black beech, explaining about 55% of the variation in growth rates. Treatment history (thinnings), as well as the individual tree size and the stand basal area, strongly affected tree diameter growth. Only 3% of the variation in diameter growth rates was explained by plot-specific effect which was less than observed in earlier studies. Conclusions: All predictor variables (management history, individual tree diameter and stand basal area) are quite simple to measure in the field and could be easily used to predict diameter increments in managed or unmanaged forests. A limitation of our study was that available growth data in Woodside were from small plots, focused on a small number of trees and a narrow range of diameters. However, our results are a good starting point, providing a promising framework for further modelling of tree growth in Woodside forest from new permanent plot data. 2017-12-01T00:00:00Z