Report 27. The effects of Leucaena hedgerow management on maize and hedgerow biomass yields over two years of cropping

Abstract

The objectives of the study were to identify optimum hedgerow management practices for alley cropping in order to optimize crop yield and hedgerow biomass production under lowland conditions in Haiti. The following treatment combinations were tested: three pruning utilization treatments, (1) prunings removed, (2) prunings applied as mulch and (3) prunings incorporated at maize planting, with subsequent application as mulch; by three pruning regimes, (a) at planting and 30 days after planting (DAP), (b) at planting and 40 DAP and (c) at planting, 30 DAP and 60 DAP. A dry wall treatment was included as a control. Stone Walls vrs. Alley Cropping - During the first year of the trial, higher yields were obtained with the stone wall treatment than with alley cropping. During the second year, the best alley crop treatments gave the same yield as the stone wall control. - Maize yields steadily declined over time in the stone wall control treatment, but remained steady in the best alley cropping treatments. - The amount of nitrogen contributed by the hedgerow prunings is estimated to be substantial. Hedgerow Management Hedgerow pruning regime and mode of utilization of prunings had important effects on crop and biomass yields. The accompanying figure shows the effects of these factors in the fourth growing season: - Removal of hedgerow prunings resulted in lower maize yields but had little effect on hedgerow biomass yields. - Incorporation of the first pruning at planting time did not improve maize yields, as compared to prunings used as mulch. - Pruning three times, at planting and 30 and 60 days after planting, resulted in higher maize yields than pruning only twice. - Highest hedgerow biomass yields were obtained by pruning at planting and at 40 days after planting. Implications for Haitian Farmers - Use of stone walls as a barrier to erosion is of itself inadequate to maintain yields over time. - Removal of hedgerow prunings to feed livestock also results in declining yields over time without other means of replenishing nutrients and organic matter in the soil. - Application of hedgerow prunings to the soil, either as mulch or incorporated, sustains crop yields. - Alternative strategies for meeting livestock forage needs are required if the goal is to improve soil fertility. Recommendations for PLUS Extension Effort - PLUS should continue to encourage the planting and maintaining of hedgerows. - PLUS should emphasize the importance of soil application of hedgerow prunings to sustain crop yields. - PLUS should emphasize the importance of timeliness of hedgerow pruning. - PLUS should identify other means for meeting livestock forage requirements which should complement rather than compete with cropping needs. Recommendations for Adaptive Research and M&E - Results from the hedgerow management trial should be combined with on-farm data to refine the financial assessment of hedgerows. - Analysis of leaf and branch samples for nitrogen content is needed to more accurately estimate the contribution of hedgerow biomass to the crop under various hedgerow management systems. - Greater attention should be given to hedgerow management and pruning use in M&E studies of hedgerows. - The present trial should continue in order to determine management effects over a longer period. - Testing is needed at other locations to refine recommendations on pruning regime under varying rainfall and soil conditions and with other crops.

Objektif étid sa-a se chèche, nan kondisyon peyi Dayiti, pi bon jan pou travay ak ranp vivan pou ogmante randman kilti nan mitan ranp yo ak randman ranp yo tou. Nou te konpare kèk jan pou travay ak ranp lesena. Nou te etidye twa fason pou itilize fèy ak branch vèt lesena ki nan ranp yo: (1) retire nan jaden an fèy ak branch ki rekòlte nan ranp yo, (2) simen fèy ak branch ki rekòlte yo nan mitan ranp yo, (3) mete fèy ak branch yo anba tè nan premye koup la, answit simen yo nan mitan ranp yo nan lòt koup yo. Twa fason sa yo te konbine ak twa dat koup ki fèt sou ranp lesena yo: (a) lè n'ap simen lòt kilti a, answit 30 jou apre, (b) lè n'ap simen lòt kilti a, answit 40 jou apre, (c) lè n'ap simen lòt kilti a, answit 30 ak 60 jou apre. Temwen yo te genyen misèk ladan yo. Konparezon Misèk ak Ranp Lesena - Nan premye lane etid la, mayi ki te simen nan mitan misèk yo bay plis randman pase mayi nan mitan ranp lesena yo. Nan dezièm lane a, misèk yo bay menm randman ak pi bon tretman nou te etidye a (twa koup ak itilizasyon fèy ak branch). - Nan mitan misèk yo, randman mayi a te bese apre chak sezon. Nan mitan ranp yo, pou pi bon tretman nou te itilize a, randman mayi a pat janm bese sezon apre sezon. - Kantite azòt fèy ak branch vèt lesena yo te pote te kont. Jesyon Ranp Jesyon ranp lesena yo enpòtan pou randman kilti ak randman ranp yo tou. Desen ki sou figi a montré efè jesyon an sou randman mayi ak pwodiksyon lesena nan katryèm sezon an. - Lè nou retire fèy ak branch lesena ki rekolte nan jaden an, randman mayi a bese men pratik sa a pa twò change pwodiksyon lesena a. - Mete fèy ak branch vèt lesena nou rekolte yo anba tè nan premye koup la bay menm randman mayi ak teknik simen fèy ak branch vèt nan mitan ranp yo. - Lè nou fè twa (3) koup (lè n'ap simen, answit 30 ak 60 jou apre), nou jwen plis randman mayi pase lè nou fè de (2) koup. - Lè nou fè twa (3) koup (lè n'ap simen, answit 30 ak 60 jou apre), lesena yo pwodwi mwens pase lè nou fè de (2) koup. - Nou te jwen plis randman lesena lè nou fè de (2) koup (lè n'ap simen ak 40 jou apre). Empòtans travay sa-a pou plantè yo - Itilizasyon misèk pou konbat ewozyon pa pèmèt an menm tan bon jan pwodiksyon pou lontan. - Itilizasyon fèy ak branch vèt lesena kòm manje bèt ap fè randman kilti yo bese si lòt teknik pa fèt pou ranplase matyè òganik yo. - Aplikasyon fèy ak branch vèt lesena sou tè a oubyen mete yo anba tè ka kenbe randman kilti yo pou lontan. - Li nesesè pou plantè yo ta jwenn yon lòt mwayen pou bay bèt yo manje. Rekòmandasyon pou Pwojè PLUS - Li nesesè pou pwojè PLUS kontinye ankouraje moun plante ak pranswen ranp vivan. - PLUS dwe travay pou fè konprann pi byen enpòtans aplikasyon fèy ak branch lesena sou tè a genyen sou randman kilti yo. - PLUS dwe travay pou fè konprann enpòtans dat koup ranp vivan yo genyen sou randman kilti. - PLUS dwe ede chèche lòt fason pou bay bèt manje ki ta dwe sèvi kòm konpleman men ki pa la pou fè konpetisyon ak bezwen kilti yo. Rekòmandasyon pou Rechèch kay peyizan ak M&E - Rezilta sa yo dwe konbine ak rezilta travay rechèch kay peyizan pou fè travay evalwasyon ekonomik ranp vivan yo pi konplè. - Analiz fèy ak branch lesena yo nesesè pou byen estime kantite azòt chak kalite jesyon pote pou kilti a. - Plis atansyon dwe bay sou jesyon ranp ak itilizasyon rekòt ranp yo nan kad etid M&E (swivi ak evalwasyon) kap fèt sou ranp vivan. - Travay sa-a dwe kontinye pou wè efè jesyon an sou yon periòd ki pi long. - Lòt etid nesesè nan lòt zòn pou bon jan rekòmandasyon sou lè pou fè koup ranp la nan divès kondisyon lapli ak kalité tè ak sou lòt kilti tou.