Farmers often resort to an occasional tillage (strategic tillage (ST)) operation to combat constraints of no-tillage (NT) farming systems. There are conflicting reports regarding impacts of ST and a lack of knowledge around when, where and how ST is implemented to maximise its benefits without impacting negatively on soil and environment. We established 14 experiments during 2012-2015 on farms with long-term history of continuous NT to (i) quantify the associated risks and benefits to crop productivity, soil and environmental health and (ii) explore key factors that need to be considered in decisions to implement ST in an otherwise NT system. Results showed that introduction of ST reduced weed populations and improved crop productivity and profitability in the first year after tillage, with no impact in subsequent 4 years. Soil properties were not impacted in Vertosols; however, Sodosols and Dermosols suffered short-term negative soil health impacts (e.g. increased bulk density). A Sodosol and a Dermosol also posed higher risks of runoff and associated loss of nutrients and sediment during intense rainfall after ST. The ST reduced plant available water in the short term, which could result in unreliable sowing opportunities for the following crop especially in semi-arid climate that prevails in north-eastern Australia. The results show that generally, there were no significant differences in crop productivity and soil health between tillage implements and tillage frequencies between ST and NT. The study suggests that ST can be a viable strategy to manage constraints of NT systems, with few short-term soil and environmental costs and some benefits such as short-term farm productivity and profitability and reduced reliance on herbicides.

The adoption of no-till farming systems has greatly reduced energy and machinery inputs while significantly improving soil health and productivity. However, the control of crop weeds and diseases in no-till (NT) systems has become increasingly difficult for landholders in Australia’s northern grains regions, with occasional strategic tillage (ST) being considered as a potential management option. This study investigated the effects of occasional ST on physical, chemical and biological soil properties, productivity, and weed control on five long-term (7–44 years) NT-managed soils. The study area extended from Biloela (Vertosol, 666 mm annual rainfall), Condamine (Sodosol, 624 mm annual rainfall), Moonie (Dermosol, 636 mm annual rainfall) and Warwick (Vertosol, 675 mm annual rainfall) in Queensland to Wee Waa (Vertosol, 582 mm annual rainfall) in New South Wales. Tillage treatments included chisel, offset disc and prickle–disc chain with various timings and frequencies. Soil samples (0–0.3 m) obtained 3 and 12 months after occasional ST were analysed for total and particulate organic carbon (TOC, POC), available phosphorus (P), bulk density, soil water, and microbial enzymatic activity. In-crop weed density was also recorded. One-time tillage, with chisel tines, offset disc or chain harrows, in long-term NT helped to control winter weeds in the first year, with variable results in the second year. Grain yield overall showed no significant impact in either year, except on the Brown Sodosol (P = 0.08) in the first year. The initial impacts of strategic tillage on soil water were largely restricted to the 0–0.1 m depth range, with slight, non-significant decreases occurring. Available P, TOC, POC and total microbial enzymatic activity were not significantly impacted by either cultivation frequency or implement type. The use of an occasional ST for the purpose of weed control could be utilised as a viable management option for NT systems in the region without impacting on long-term productivity.

Large cardamom is one of the most important spices that can significantly contribute to the economical farming in the country of Nepal. It is grown in Nepal and north-eastern states of India which provide suitable agroclimatic growing conditions of high humidity, ambient temperature and high rainfall. Meeting the demand for high quality plants and yield of cardamom is challenging with traditional methods of propagation. The present study has used the plant tissue culture technique to produce high quality plants. In this regard, MS media with three different hormonal combinations were used for the development protocol for 8 weeks. Shoot length, root length, shoot number and root number were assessed at intervals. The best protocol for growth was MS media with 1 mg/L BAP + 0.5 mg/L IBA for the Ramsey variety, with no significant difference for Golsai, Dambarsai, or Sikkimae varieties. Similarly, the acclimatization and field transfer study was done. The use of any substrate composition in ratio of coco peat: soil 1:2; moss: coco peat 1:2 and sawdust: coco peat 1:2 enables transfer of healthy plants to the field. The results indicate that the varieties respond differently to the micropropagation process and to hormone concentrations indicated by differing root and shoot production. The protocol of 1mg/L BAP and 0.5mg/L IBA could be used for the Ramsai while optimal shoot production for Golsai and Sikkimae should be at 0.5mg/L and 5mg/L for shoot production. All varieties showed optimal root production at 0mg/L BAP and 0.5mg/L IBA. This study sheds light on the different responsiveness of varieties to tissue culture and hormone concentrations for both root and shoot development in micropropagation.