Abstract No yield differences in tops or roots were measured between ammonium and nitrate nitrogen sources flow ‘United 108’ grown for 14 28 days constant culture solution. There was a greater uptake of N from the source but approximately 25% total remained as within plant. Higher plant levels phosphorus sulphur treatment higher Ca ++ Mg indicating predominately cation‐anion balance effect.

The soil survey was conducted on cropped and uncropped Red Earths (Alfisols), Grey Clays, Black (Vertisols) in northern New South Wales. degradation of physical properties between the reference sites reflected declines 29–86% hydraulic conductivity (K) 33–71% aggregation. Generally there a substantial loss carbon with cropping, labile (CL) usually greater than total (CT). A Clay which had been for >40 years lost 63% 51% its CL CT, respectively. An adjacent cleared only 2 43% 26%...

Abstract The addition of NH 4 + ions to a fertilizer P band is known increase the absorption P. This study was conducted further clarify mechanisms responsible for this phenomenon. Pellets 33 labelled monocalcium phosphate (MCP), MCP K 2 SO or (NH ) were placed 1.25 cm side corn root tip growing in soil at surface box with sloping removable front. Roots vicinity pellet, and shoots, harvested 15 days later. Fertilizer concentration shoots doubled by tripled . Autoradiographs area surrounding...

Sugarcane cropping produces a large amount of crop residues, which offers considerable scope for residue management. Soil samples, collected from 2 long-term experiments in Australia and an experiment Pernambuco State, Brazil, were analysed total carbon (CT) labile (CL) by oxidation with 333 mM KMnO4. At the locations Australia, CT CL concentrations lower surface layer (0-1 cm) cropped soil compared nearby uncropped reference soil. Burning resulted greater loss at depth 0-1 cm than green...

Abstract. Seventeen field experiments were conducted on alkaline soils in eastern Australia between 1997 and 2000 to evaluate irrigated cotton response phosphorus (P) fertilisation. Only 3 demonstrated significant (P < 0.05) increases crop P uptake or lint yield with application. Comparison of several soil tests revealed that Colwell (bicarbonate) provided the best correlation at early flowering yield. Soil may limit growth where Colwell-P concentrations are <6 mg/kg. most sites well...

Abstract The objective of this study was to test the hypothesis that reduction pH at soil‐root interface when NH 4 + ions were absorbed is cause increased absorption P in presence . influence addition (NH ) 2 SO or KNO 3 an MCP band on by corn determined a greenhouse involving four soils ranging from 4.2 8.2. in‐situ activity plants periodically during growth, and dry weight tops roots fertilizer zone as well nutrient content after 17 days. Application with found increase uptake compared...

The contribution of cotton stubble to the soil organic matter content Vertisols under production is not well understood. A 3-year experiment was conducted at Australian Cotton Research Institute study effects burning and incorporating on recovery fertiliser nitrogen (N), lint yield, levels. This reports changes in fractions as affected by into soil. Soil samples collected start end were analysed for total carbon (CT), N (NT), δ13C (a measure 13C/12C isotopic ratios). Labile (CL) determined...

Management of organic matter in soils requires techniques that accurately monitor changes soil over the short term and long term. This study was carried out a glasshouse pot experiment to examine carbon under influence long-term cropping, plant residue, fertiliser application, using variations 13C/12C isotopic ratios materials fractionation by ease oxidation. The examines contents adjacent samples with different cropping histories as affected application crop residue growth wheat....

Soils of Cambodia are low in fertility and conventional rice cultivation destroys any structure that they have. Usage inorganic fertilizers is farmers encouraged to use animal manure. Much the research conducted on crop responses manure based trials where unrealistically high application rates have been used so given false hopes as what might achieve through its use. Little response curve data exists which base fertilizer rate recommendations general formulated for different soil groups. An...

Abstract Most previous experiments examining factors affecting the conversion of elemental S into plant‐available forms have used indirect methods, such as measuring sulfate accumulation, and at times resulted in exaggerated estimates oxidation rates. Direct measurement residual offers a more reliable estimate rate, but only some known to affect rate been investigated by direct methods. A pot experiment was conducted over 238 days measure rates under range particle sizes (0.1–2.0 mm) soil...