Chicken Litter as Fertiliser for Broadacre Grain Crops a user’s guide Page 2 Increasing costs of fertilisers What is chicken litter’s has many broadacre cropping potential as fertiliser? farmers considering alternative nutrient sources to apply to Nutrient Content crops. Phosphorus-based fertiliser Chicken litter contains useful amounts of prices have been particularly phosphorus, nitrogen and potassium as volatile and expensive in recent well as trace elements zinc, manganese years. and copper. Nutrient contents can vary considerably between sources and Spent litter associated with batches.. broiler chicken production has gained attention from grain Moisture Nitrogen (N) Phosphorus (P) Potassium (K) Sulphur (S) Litter Type/Base (%) (%dwt) (kg/t fwt) (%dwt) (kg/t fwt) (%dwt) (kg/t fwt) (%dwt) (kg/t fwt) farmers in districts with chicken Average 20 4.0 32.1 1.1 8.6 2.2 17.2 0.63 5.0 farms close at hand. It contains Straw Range 14.5 - 25.1 2.0 - 5.3 0.7 - 1.8 1.6 - 2.8 0.5 - 1.1 a variety of plant nutrients and Average 25 3.8 28.2 1.2 8.9 1.8 13.7 0.54 4.1 Sawdust is commonly used overseas as a Range 20.1 - 28.8 2.8 - 5.9 0.75 - 1.53 1.3 - 2.5 0.4 - 0.7 source of crop nutrients. Until Wood Average 26 3.9 29.0 1.3 9.9 1.9 14.0 0.51 3.8 recently, little information existed Shavings Range 20.5 - 31.2 2.8 - 5.5 0.68 - 1.7 1.1 - 2.8 0.3 - 0.7 on its use in Australian farming Multibatch Average 21 4.0 31.7 1.7 13.4 2.4 18.9 0.58 4.6 systems. Table 1: Macro nutrient content of spent chicken litter (RIRDC Litter Survey From 2007 to 2012, Rural 2010) Zinc (Zn) Copper (Cu) Manganese (Mn) Directions Pty Ltd has conducted Litter Type/Base (g/tonne fwt) (g/tonne fwt) (g/tonne fwt) two RIRDC funded research Average 296 120 416 Straw projects examining the use of Range 128-400 88-168 312-664 chicken litter as a broadacre Average 270 113 300 Sawdust crop fertiliser in South Australia. Range 218-383 60-158 210-413 The project aimed to address Wood Average 318 96 355 frequently asked questions posed Shavings Range 200-437 59-222 259-570 by broadacre users of chicken Average 427 98 521 Multibatch litter, and provide practical Range 346-529 80-119 450-585 information on its use. Findings Table 2: Micro nutrient content of spent from the projects have been chicken litter (RIRDC Litter Survey 2010) used to develop this guide for NB - %dwt = percentage dry weight; kg/t fwt = kilogram of nutrient per tonne of litter fresh weight; g/tonne fwt = grams of micronutrient per grain producers considering tonne of litter fresh weight. chicken litter as an alternative fertiliser. Variability in Nutrient Levels Nutrient levels can vary by 100% or more Tip: Request an analysis between litter sources and batches. Given of the litter you intend this variability, it is important to obtain a to purchase to check nutrient content analysis of the product nutrient content, purchased to make sure it represents good particularly phosphorus. value. Don’t assume that what you are This analysis can be told will be in there is actually present in carried out at several the litter. laboratories for around $30-$50 per sample. Fresh litter contains 20% to 30% moisture. Nutrient contents are generally Alternatively, be quoted as percentage of dry weight conservative in your (%dwt). When calculating the amount estimation of nutrient of nutrient to be applied, the nutrient content to prevent content used in calculations needs to under application. be reduced proportionately to provide a realistic estimate. Page 3 Nutrient availability, Figure 1 displays the results of trials where chicken litter was applied with and without conventional fertiliser on a phosphorus responsive (low phosphorus) and a accessibility and losses non-phosphorus responsive (high phosphorus) soil. Starter fertiliser in the seed row was important to maintain yield at the phosphorus responsive soil, but there was no Phosphorus advantage on the non-responsive soil. In trials on some soils, crops treated with Figure 1: Wheat yield in response to combinations of chicken litter and chicken litter showed less early vigour conventional fertiliser applications at phosphorus responsive and phosphorus compared to crops sown with conventional non-responsive sites at Freeling, SAGrainYield in 2010 fertiliser in close proximity to the seed, 6.00 particularly in low disturbance sowing systems. In most cases eventual grain yield A 5.00 A A was not affected, however, there were A A instances where yields were slightly lower than where conventional fertiliser was 4.00 applied. A A 3.00 The likely cause of vigour reductions is B B A B from the nutrients in chicken litter being 2.00 Responsive either less available, or less accessible Yield (t/ha) for uptake by the roots of the establishing Non Responsive crop. 1.00 Much of the nutrient in chicken litter 0.00 occurs in an organic form. As a result, microbial breakdown of the litter in the soil may temporarily ‘tie-up’ nutrients during the decomposition process. In addition, litter is mostly applied by broadcasting several weeks prior to seeding with no-till equipment (knife Tip: Use starter applications of Other Macronutrients points and presswheels). Minimal conventional fertiliser in the seed incorporation of the litter occurs during row, rather than using chicken Chicken litter also contains useful the seeding process and as a result litter alone if unsure of your quantities of potassium and sulphur which minimal litter ends up in the seed row in paddock’s soil phosphorus status. can provide added value in soil types close proximity to the roots of germinating requiring additions of these nutrients. crop seedlings. Trace Elements In most cases, the reduction in vigour is Nitrogen Chicken litter contains some trace phosphorus related. Vigour reductions are elements. Zinc, copper and manganese less likely in crops grown in soils with high Although chicken litter contains potentially are commonly deficient in many background levels of available phosphorus. useful amounts of nitrogen, a proportion cropping soils. Chicken litter provides an Grain analysis in field trials indicate of the nitrogen is lost as ammonia gas opportunity to contribute to soil reserves lower levels of grain phosphorus in plots between spreading and incorporation via of these nutrients. receiving chicken litter alone, compared the seeding operation. Loss rates are quite with those treated with conventional high, with up to 25% lost as ammonia As with phosphorus, accessibility of trace phosphorus fertiliser, helping to support from raw litter products in the week elements by the roots of establishing crops this explanation. following application, particularly during is limited due to the nature of application warm weather. More than 50% can be and subsequent incorporation. Foliar In most cases, the reduction in vigour lost if the litter remains on the soil surface nutrient applications may be required for is phosphorus related. Vigour and yield for extended periods without rainfall or these nutrients in potential deficiency reductions are less likely in crops grown physical incorporation. situations, particularly in the short term in soils with high background levels of after litter is applied. available phosphorus. Immediate incorporation by cultivation or rainfall following application can increase This problem is overcome when a “starter” the amount of nitrogen “preserved” for Tip: Although chicken litter provides application of some conventional fertiliser use by the crop. This, however, is often useful amounts of trace elements to build is applied in the seed row of the crop, impractical, or the negative effect of the soil levels in the longer term, be in conjunction with the application additional cultivation on soil structure prepared to address potential deficiencies of chicken litter. Depending on the outweighs the potential benefit from the with foliar nutrient sprays in crops phosphorus levels in the soil, often the additional nitrogen. As a result, when raw grown on deficient soils. rates of conventional fertiliser required to chicken litter is applied without immediate overcome this problem are significantly less incorporation, estimations of the nitrogen than standard rates. supplied may need to be discounted by up to 50% to account for losses. Page 4 How do I use chicken Soils with good phosphorus levels are Chicken Litter as a Soil also suited to chicken litter applications, Improver litter on broadacre crops? but with a slightly different objective. The aim of applying chicken litter may be to Growers in some cropping districts are Raw chicken litter is a light, bulky product, further build soil phosphorus reserves, applying high rates of chicken litter to which requires high volume specialised with a view to “mining” those reserves poor producing or problem soils in an spreaders to spread the litter effectively. in future years (particularly in years when attempt to improve them. Low fertility Compared to conventional fertilisers which conventional fertilisers are very expensive) sand hills and low organic matter, hard- are applied during the sowing operation, by applying less than maintenance rates of setting areas are particularly targeted with the time required and costs of applying conventional fertiliser. rates of chicken litter 2 to 5 times higher chicken litter per hectare can be high. than district practice rates with the aim of Given the time and logistics involved, for Beware of Applying too Much supplying high quantities of nutrients and most growers it is an impossible task to Nitrogen organic matter to boost fertility levels. treat their entire cropping area in one year.