Extended use of poultry manure as a nutrient source for flood-irrigated rice crop

Abstract: The objective of this work was to evaluate changes in the soil chemical properties, nitrogen use efficiency, and grain yield of flood-irrigated rice fields after the addition of poultry manure during five years. Trials were carried out in a randomized complete block design, with three replicates. The treatments were: chemical fertilizers, N-P2O5-K2O; control, no fertilizers; and poultry manure doses, 2.5, 5.0, and 10.0 Mg ha-1. Poultry manure increased soil pH, base saturation, and phosphorus, potassium, calcium, and zinc contents more than the chemical fertilizers. Adding poultry manure to the soil increased N ammonification (35 mg kg-1 NH4 +-N) from the first to the fourth week after rice was sown. The exclusive use of poultry manure was not sufficient to provide adequate nutrition to rice plants after the decrease in NH4 +-N content in the soil. The cumulative N uptake by plants and rice yield were lower with poultry manure application than with the chemical fertilizers. Adding poultry manure to flood-irrigated rice fields for five years alters soil chemical properties, improves fertility, does not favor nitrogen use efficiency by rice plants, and promotes a lower grain yield than the chemical fertilizers.

摘要：本研究旨在评估连续五年施用家禽粪肥后，淹水灌溉稻田的土壤化学性质变化、氮素利用效率（nitrogen use efficiency）及籽粒产量。试验采用随机完全区组设计，设置三次重复。处理组包括：化肥组（N-P₂O₅-K₂O）、对照组（不施肥），以及家禽粪肥施用量梯度组：2.5、5.0和10.0 Mg·ha⁻¹。相较于化肥处理，家禽粪肥更能提升土壤pH值、盐基饱和度，以及土壤磷、钾、钙和锌含量。在水稻播种后的第1至第4周，施用家禽粪肥可提升土壤氮氨化作用，铵态氮（NH₄⁺-N）含量可达35 mg·kg⁻¹。当土壤中铵态氮含量下降后，单独施用家禽粪肥无法为水稻植株提供充足的养分供应。相较于化肥施用，单独施用家禽粪肥时，植株的累积氮吸收量和水稻籽粒产量均更低。连续五年向淹水灌溉稻田施用家禽粪肥，可改变土壤化学性质、提升土壤肥力，但无法提升水稻的氮素利用效率，且籽粒产量较化肥组更低。